Mr. Justice Goldberg
delivered the opinion of the Court.
This appeal involves a single question: the constitutionality of § 6 of the Subversive Activities Control Act of 1950, 64 Stat. 993, 50 U. S. C. § 785. Section 6 provides in pertinent part that:
“(a) When a Communist organization ... is registered, or there is in effect a final order of the Board requiring such organization to register, it shall be unlawful for any member of such organization, with knowledge or notice that such organization is so registered or that such order has become final— “(1) to make application for a passport, or the renewal of a passport, to be issued or renewed by or under the authority of the United States; or “(2) to use or attempt to use any such passport.”
Section 6 became effective, with respect to appellants, on October 20, 1961, when a final order of the Subversive Activities Control Board issued directing the Communist Party of the United States to register under § 7 of the Subversive Activities Control Act. The registration order had been upheld earlier in 1961 by this Court’s decision in Communist Party of the United States v. Subversive Activities Control Board, 367 U. S. 1. Prior to issuance of the final registration order both appellants, who are native-born citizens and residents of the United States, had held valid passports. Subsequently, on January 22, 1962, the Acting Director of the Passport Office notified appellants that their passports were revoked because the Department of State believed that their use of the passports would violate § 6. Appellants were also notified of their right to seek administrative review of the revocations under Department of State regulations.
Appellants requested and received hearings to review the revocations of their passports. The respective hearing examiners concluded that “the Department of State had reason to believe that [appellants are] within the purview of Section 6 (a)(2) of the Subversive Activities Control Act . . . and as a result thereof . f . use of a passport would be in violation of the law.” On the basis of this conclusion the examiners recommended that the passport revocations be sustained. Both appellants appealed to the Board of Passport Appeals which recommended affirmance of the revocations. The Secretary of State subsequently approved the recommendations of the Board. The Secretary stated that he “relied solely on the evidence in the record” and that, as the basis of his decision, he:
“specifically adopted as his own the [Board’s] finding of fact that 'at all material times [appellants were members] of the Communist Party of the United States with knowledge or notice that such organization had been required to register as a Communist organization under the Subversive Activities Control Act.’ ”
Appellants thereupon filed separate complaints seeking declaratory and injunctive relief in the United States District Court for the District of Columbia. The complaints, which have been considered together, asked that judgments be entered declaring § 6 of the Subversive Activities Control Act unconstitutional and ordering the Secretary of State to issue passports to appellants. Each appellant-plaintiff alleged that § 6 was unconstitutional as, inter alia, “a deprivation without due process of law of plaintiff’s constitutional liberty to travel abroad, in violation of the Fifth Amendment to the Constitution of the United States.” Appellants conceded that the Secretary of State had an adequate basis for finding that they were members of the Communist Party of the United States and that the action revoking their passports was proper if § 6 was constitutional. The parties agreed that all administrative remedies had been exhausted and that it would be futile, and indeed a criminal offense, for either appellant to apply for a passport while remaining a member of the Communist Party.
The three-judge District Court, which was convened to review the constitutional question, rejected appellants’ contentions, sustained the constitutionality of § 6 of the Control Act, and granted the Secretary’s motion for summary judgment. 219 F. Supp. 709. The court concluded that:
“the enactment by Congress of section 6, which prohibits these plaintiffs from obtaining passports so long as they are members of an organization — in this case the Communist Party — under a final order to register with the Attorney General ... is a valid exercise of the power of Congress to protect and preserve our Government against the threat posed by the world Communist movement and that the regulatory scheme bears a reasonable relation thereto.” Id., at 714.
This Court noted probable jurisdiction. 375 U. S. 928.
Appellants attack § 6, both on its face and as applied, as an unconstitutional deprivation of the liberty guaranteed in the Bill of Rights. The Government, while conceding that the right to travel is protected by the Fifth Amendment, contends that the Due Process Clause does not prevent the reasonable regulation of liberty and that § 6 is a reasonable regulation because of its relation to the danger the world Communist movement presents for our national security. Alternatively, the Government argues that “whether or not denial of passports to some members of the Communist Party might be deemed not reasonably related to national security, surely Section 6 was reasonable as applied to the top-ranking Party leaders involved here.”
' We hold, for the reasons stated below, that § 6 of the Control Act too broadly and indiscriminately restricts the right to travel and thereby abridges the liberty guaranteed by the Fifth Amendment.
I.
In 1958 in Kent v. Dulles, 357 U. S. 116, 127, this Court declared that the right to travel abroad is “an important aspect of the citizen’s ‘liberty’ ” guaranteed in the Due Process Clause of the Fifth Amendment. The Court stated that:
“The right to travel is a part of the ‘liberty’ of which the citizen cannot be deprived without due process of law under the Fifth Amendment. . . . Freedom of movement across frontiers in either direction, and inside frontiers as well, was a part of our heritage. Travel abroad, like travel within the country, . . . may be as close to the heart of the individual as the choice of what he eats, or wears, or reads. Freedom of movement is basic in our scheme of values.” Id., at 125-126.
In Kent, however, the Court concluded that Congress had not conferred authority upon the Secretary of State to deny passports because of alleged Communist beliefs and associations. Therefore, although the decision protected the constitutional right to travel, the Court did not examine “the extent to which it can be curtailed.” Id., at 127. The Court, referring to § 6 of the Subversive Activities Control Act, noted that “the only law which Congress has passed expressly curtailing the movement of Communists across our borders has not yet become effective.” Id., at 130. Two years later in Communist Party of the United States v. Subversive Activities Control Board, supra, this Court reviewed and upheld the registration requirement of § 7 of the Control Act. The Court, however, did not pass upon the “various consequences of the Party’s registration for its individual members,” id., at 70, because:
“It is wholly speculative now to foreshadow whether, or under what conditions, a member of the Party may in the future apply for a passport, or seek government or defense-facility or labor-union employment, or, being an alien, become a party to a naturalization or a denaturalization proceeding. None of these things may happen. If they do, appropriate administrative and judicial procedures will be available to test the constitutionality of applications of particular sections of the Act to particular persons in particular situations. Nothing justifies previsioning those issues now.” Id., at 79. (Emphasis added.)
The present case, therefore, is the first in which this Court has been called upon to consider the constitutionality of the restrictions which § 6 imposes on the right to travel.
The substantiality of the restrictions cannot be doubted. The denial of a passport, given existing domestic and foreign laws, is a severe restriction upon, and in effect a prohibition against, world-wide foreign travel. Present laws and regulations make it a crime for a United States citizen to travel outside the Western Hemisphere or to Cuba without a passport. By its plain import § 6 of the Control Act effectively prohibits travel anywhere in the world outside the Western Hemisphere by members of any “Communist organization” — including “Communist-action” and “Communist-front” organizations. The restrictive effect of the legislation cannot be gainsaid by emphasizing, as the Government seems to do, that a member of a registering organization could recapture his freedom to travel by simply in good faith abandoning his membership in the organization. Since freedom of association is itself guaranteed in the First Amendment, restrictions imposed upon the right to travel cannot be dismissed by asserting that the right to travel could be fully exercised if the individual would first yield up his membership in a given association.
Although previous cases have not involved the constitutionality of statutory restrictions upon the right to travel abroad, there are well-established principles by which to test whether the restrictions here imposed are consistent with the liberty guaranteed in the Fifth Amendment. It is a familiar and basic principle, recently reaffirmed in NAACP v. Alabama, 377 U. S. 288, 307, that “a governmental purpose to control or prevent activities constitutionally subject to state regulation may not be achieved by means which sweep unnecessarily broadly and thereby invade the area of protected freedoms.” See, e. g., NAACP v. Button, 371 U. S. 415, 438; Louisiana ex rel. Gremillion v. NAACP, 366 U. S. 293; Shelton v. Tucker, 364 U. S. 479, 488; Schware v. Board of Bar Examiners, 353 U. S. 232, 239; Martin v. Struthers, 319 U. S. 141,146-149; Cantwell v. Connecticut, 310 U. S. 296, 304-307; Schneider v. State, 308 U. S. 147, 161, 165. In applying this principle the Court in NAACP v. Alabama, supra, referred to the criteria enunciated in Shelton v. Tucker, supra, at 488:
“[E]ven though the governmental purpose be legitimate and substantial, that purpose cannot be pursued by means that broadly stifle fundamental personal liberties when the end can be more narrowly achieved. The breadth of legislative abridgment must be viewed in the light of less drastic means for achieving the same basic purpose.”
This principle requires that we consider the congressional purpose underlying § 6 of the Control Act. The Government emphasizes that the legislation in question flows, as the statute itself declares, from the congressional desire to protect our national security. That Congress under the Constitution has power to safeguard our Nation’s security is obvious and unarguable. Cf. Kennedy v. Mendoza-Martinez, 372 U. S. 144, 159-160. As we said in Mendoza-Martinez, “while the Constitution protects against invasions of individual rights, it is not a suicide pact.” Id., at 160. At the same time the Constitution requires that the powers of government “must be so exercised as not, in attaining a permissible end," unduly to infringe” a constitutionally protected freedom. Cantwell v. Connecticut, supra, at 304.
Section 6 provides that any member of a Communist organization which has registered or has been ordered to register commits a crime if he attempts to use or obtain a United States passport. The section applies to members who act “with knowledge or notice” that the organization is under a final registration order. “Notice” is specifically defined in § 13 (k). That section provides that publication in the Federal Register of the fact of registration or of issuance of a final registration order “shall constitute notice to all members of such organization that such order has become final.” Thus the terms of § 6 apply whether or not the member actually knows or believes that he is associated with what is deemed to be a “Communist-action” or a “Communist-front” organization. The section also applies whether or not one knows or believes that he is associated with an organization operating to further aims of the world Communist movement and “to establish a Communist totalitarian dictatorship in the countries throughout the world . . .
64 Stat. 987, 50 U. S. C. § 781 (1). The provision therefore sweeps within its prohibition both knowing and unknowing members. In related contexts this Court has had occasion to consider the substantiality of the relationship between an individual and a group where, as here, the fact of membership in that group has been made the sole criterion for limiting the individual's freedom. In Wieman v. Updegraff, 344 U. S. 183, the Court held that the due process guarantee of the Constitution was violated when a State, in an attempt to bar disloyal individuals from its employ, excluded persons solely on the basis of organizational memberships without regard' to their knowledge concerning the organizations to which they had belonged. The Court concluded that: “Indiscriminate classification of innocent with knowing activity must fall as an assertion of arbitrary power.” Id., at 191.
Section 6 also renders irrelevant the member’s degree of activity in the organization and his commitment to its purpose. These factors, like knowledge, would bear on the likelihood that travel by such a person would be attended by the type of activity which Congress sought to control. As the Court has elsewhere noted, “men in adhering to a political party or other organization notoriously do not subscribe unqualifiedly to all of its platforms or asserted principles.” Cf. Schneiderman v. United States, 320 U. S. 118, 136. It was in this vein that the Court in Schware v. Board of Bar Examiners, 353 U. S., at 246, stated that even “[a]ssuming that some members of the Communist Party . . . had illegal aims and engaged in illegal activities, it cannot automatically be inferred that all members shared their evil purposes or participated in their illegal conduct.” Section 6, however, establishes an irrebuttable presumption that individuals who are members of the specified organizations will, if given passports, engage in activities inimical to the security of the United States.
In addition to the absence of criteria linking the bare fact of membership to the individual’s knowledge, activity or commitment, § 6 also excludes other considerations which might more closely relate the denial of passports to the stated purpose of the legislation. The prohibition of § 6 applies regardless of the purposes for which an individual wishes to travel. Under the statute it is a crime for a notified member of a registered organization to apply for a passport to travel abroad to visit a sick relative, to receive medical treatment, or for any other wholly innocent purpose. In determining whether there has been an abridgment of the Fifth Amendment’s guarantee of liberty, this Court must recognize the danger of punishing a member of a Communist organization “for his adherence to lawful and constitutionally protected purposes, because of other and unprotected purposes which he does not necessarily share.” Noto v. United States, 367 U. S. 290, 299-300; Scales v. United States, 367 U. S. 203, 229-230. In addition it must be noted that § 6 applies to a member regardless of the security-sensitivity of the areas in which he wishes to travel. As a result, if a notified member of a registered organization were to apply for a passport to visit a relative in Ireland, or to read rare manuscripts in the Bodleian Library of Oxford University, the applicant would be guilty of a crime; whereas, if he were to travel to Canada or Latin America to carry on criminal activities directed against the United States, he could do so free from the prohibitive reach of § 6.
In determining the constitutionality of § 6, it is also important to consider that Congress has within its power “less drastic” means of achieving the congressional objective of safeguarding our national security. Shelton v. Tucker, 364 U. S., at 488. The Federal Employee Loyalty Program, which was before this Court in Joint Anti-Fascist Refugee Comm. v. McGrath, 341 U. S. 123, provides an example. Under Executive Order No. 9835, membership in a Communist organization is not considered conclusive but only as one factor to be weighed in determining the loyalty of an applicant or employee. It is relevant to note that less than a month after the decision in Kent v. Dulles, supra, President Eisenhower sent a message to Congress stating that: “Any limitations on the right to travel can only be tolerated in terms of overriding requirements of our national security, and must be subject to substantive and procedural guaranties.” Message from the President — Issuance of Passports, H. Doc. No. 417, 85th Cong., 2d Sess.; 104 Cong. Rec. 13046. The legislation which the President proposed did not make membership in a Communist organization, without more, a disqualification for obtaining a passport. S. 4110, H. R. 13318, 85th Cong., 2d Sess. Irrespective of views as to the validity of this or other such proposals, they demonstrate the conviction of the Executive Branch that our national security can be adequately protected by means which, when compared with § 6, are more dis-criminately tailored to the constitutional liberties of individuals.
In our view the foregoing considerations compel the conclusion that § 6 of the Control Act is unconstitutional on its face. The section, judged by its plain import and by the substantive evil which Congress sought to control, sweeps too widely and too indiscriminately across the liberty guaranteed in the Fifth Amendment. The prohibition against travel is supported only by a tenuous relationship between the bare fact of organizational membership and the activity Congress sought to proscribe. The broad and enveloping prohibition indiscriminately excludes plainly relevant considerations such as the individual's knowledge, activity, commitment, and purposes in and places for travel. The section therefore is patently not a regulation “narrowly drawn to prevent the supposed evil,” cf. Cantwell v. Connecticut, 310 U. S., at 307, yet here, as elsewhere, precision must be the touchstone of legislation so affecting basic freedoms, NAACP v. Button, 371 U. S., at 438.
II.
The Government alternatively urges that, if § 6 cannot be sustained on its face, the prohibition should nevertheless be held constitutional as applied to these particular appellants. The Government argues that “surely Section 6 was reasonable as applied to the top-ranking Party leaders involved here.” It is not disputed that appellants are top-ranking leaders: Appellant Aptheker is editor of Political Affairs, the “theoretical organ” of the Party in this country and appellant Flynn is chairman of the Party.
It must be remembered that “[a]lthough this Court will often strain to construe legislation so as to save it against constitutional attack, it must not and will not carry this to the point of perverting the purpose of a statute . . .” or judicially rewriting it. Scales v. United States, supra, at 211. To put the matter another way, this Court will not consider the abstract question of whether Congress might have enacted a valid statute but instead must ask whether the statute that Congress did enact will permissibly bear a construction rendering it free from constitutional defects.
The clarity and preciseness of the provision in question make it impossible to narrow its indiscriminately cast and overly broad scope without substantial rewriting. The situation here is different from that in cases such as United States v. National Dairy Products Corp., 372 U. S. 29, where the Court is called upon to consider the content of allegedly vague statutory language. Here, in contrast, an attempt to “construe” the statute and to probe its recesses for some core of constitutionality would inject an element of vagueness into the statute’s scope and application; the plain words would thus become uncertain in meaning only if courts proceeded on a case-by-case basis to separate out constitutional from unconstitutional areas of coverage. This course would not be proper, or desirable, in dealing with a section which so severely curtails personal liberty.
Since this case involves a personal liberty protected by the Bill of Rights, we believe that the proper approach to legislation curtailing that liberty must be that adopted by this Court in NAACP v. Button, 371 U. S. 415, and Thornhill v. Alabama, 310 U. S. 88. In NAACP v. Button the Court stated that:
“[I]n appraising a statute’s inhibitory effect upon such rights, this Court has not hesitated to take into account possible applications of the statute in other factual contexts besides that at bar. Thornhill v. Alabama, 310 U. S. 88, 97-98; Winters v. New York, [333 U. S. 507], 518-520. Cf. Staub v. City of Baxley, 355 U. S. 313. . . . The objectionable quality of vagueness and overbreadth does not depend upon absence of fair notice to a criminally accused or upon unchanneled delegation of legislative powers, but upon the danger of tolerating, in the area of First Amendment freedoms, the existence of a penal statute susceptible of sweeping and improper application. Cf. Marcus v. Search Warrant, 367 U. S. 717, 733. These freedoms are delicate and vulnerable, as well as supremely precious in our society. The threat of sanctions may deter their exercise almost as potently as the actual application of sanctions.” 371 U. S., at 432-433.
For essentially the same reasons this Court had concluded that the constitutionality of the statute in Thornhill v. Alabama should be judged on its face:
“An accused, after arrest and conviction under such a statute [on its face unconstitutionally abridging freedom of speech], does not have to sustain the burden of demonstrating that the State could not constitutionally have written a different and specific statute covering his activities as disclosed by the charge and the evidence introduced against him.” 310 U. S., at 98.
Similarly, since freedom of travel is a constitutional liberty closely related to rights of free speech and association, we believe that appellants in this case should not be required to assume the burden of demonstrating that Congress could not have written a statute constitutionally prohibiting their travel.
Accordingly the judgment of the three-judge District Court is reversed and the cause remanded for proceedings in conformity with this opinion.
Reversed and remanded.
Paragraph 5 of § 3 of the Act provides that: “For the purposes of this subchapter . . . [t]he term ‘Communist organization’ means any Communist-action organization, Communist-front organization, or Communist-infiltrated organization.” 64 Stat. 990, as amended, 68 Stat. 777, 50 U. S. C. § 782.
Section 6 (b) provides that:
“When an organization is registered, or there is in effect a final order of the Board requiring an organization to register, as a Communist-action organization, it shall be unlawful for any officer or employee of the United States to issue a passport to, or renew the passport of, any individual knowing or having reason to believe that such individual is a member of such organization.”
The criminal penalties for violations of § 6 are specified in § 15 (c) of the Act which provides in pertinent part that:
“Any individual who violates any provision of section 5, 6, or 10 of this title shall, upon conviction thereof, be punished for each such violation by a fine of not more than $10,000 or by imprisonment for not more than five years, or by both such fine and imprisonment.” 64 Stat. 1003, 50 U. S. C. § 794 (c).
Appellants do not question that the hearings afforded them procedural due process of law. Cf. Greene v. McElroy, 360 U. S. 474.
Each complaint further alleged that § 6 was unconstitutional as: “(b) an abridgement of plaintiff’s freedoms of speech, press and assembly, in violation of the First Amendment, (c) a penalty imposed on plaintiff without a judicial trial, and therefore a bill of attainder, in violation of Article I, section 9 of the Constitution, (d) a deprivation of plaintiff’s right to trial by jury as required by the Fifth and Sixth Amendments and Article III, section 2, clause 3 of the Constitution, and (e) the imposition of a cruel and unusual punishment in violation of the Eighth Amendment.”
Our disposition of this case makes it unnecessary to review these contentions.
In Bolling v. Sharpe, 347 U. S. 497, 499-500, this Court stated that: “Although the Court has not assumed to define ‘liberty’ with any great precision, that term is not confined to mere freedom from bodily restraint. Liberty under law extends to the full range of conduct which the individual is free to pursue, and it cannot be restricted except for a proper governmental objective.”
See note 1, supra.
E. g., Brotherhood of Railroad Trainmen v. Virginia State Bar, 377 U. S. 1; Gibson v. Florida Legislative Investigation Comm., 372 U. S. 539; NAACP v. Button, 371 U. S. 415; Louisiana ex rel. Gremillion v. NAACP, 366 U. S. 293; Shelton v. Tucker, 364 U. S. 479; Bates v. City of Little Rock, 361 U. S. 516; NAACP v. Alabama ex rel. Patterson, 357 U. S. 449; Schneider v. State, 308 U. S. 147.
The purpose of the Act is stated in § 2. 64 Stat. 987, 50 U. S. C. §781. Congress found, as is generally stated in §2 (1), that there “exists a world Communist movement . . . whose purpose it is, by treachery, deceit, infiltration . . . , espionage, sabotage, terrorism, and any other means deemed necessary, to establish a Communist totalitarian dictatorship in the countries throughout the world through the medium of a world-wide Communist organization.” Congress concluded, as stated in §2 (15), that the “Communist organization in the United States” and the world Communist movement present a danger to the security of the United States, a danger requiring legislative action. The congressional purpose in adopting § 6 is more specifically stated in § 2 (8):
“Due to the nature and scope of the world Communist movement, with the existence of affiliated constituent elements working toward common objectives in various countries of the world, travel of Communist members, representatives, and agents from country to country facilitates communication and is a prerequisite for the carrying on of activities to further the purposes of the Communist movement.”
The provision in question cannot, as the Government admits, be limited by adopting an interpretation analogous to this Court’s interpretation of the so-called “membership clause” in the Smith Act. In Scales v. United States, 367 U. S. 203, the Smith Act, which imposes criminal penalties for membership, was interpreted to include only “ ‘active’ members having also a guilty knowledge and intent.” Id., at 228. The membership clause in that case, however, explicitly required “that a defendant must have knowledge of the organization’s illegal advocacy.” Id., at 221. That requirement was intimately connected with the construction limiting membership to “active” members. With regard to the Control Act, however, as the Government concedes, “neither the words nor history of Section 6 suggests limiting its application to ‘active’ members.”
In denying appellants passports the Secretary of State made no finding as to their purposes in traveling abroad. The statute, as noted, supports the Secretary’s implicit conclusion that such a finding was irrelevant. Appellants, however, in their respective complaints stated their purposes. Appellant Aptheker alleged that:
“He desires to travel to countries of Europe and elsewhere for study and recreation, to observe social, political and economic conditions abroad, and thereafter to write, publish, teach and lecture in this country about his observations. He also desires to travel abroad in order to attend meetings of learned societies and to fulfill invitations to lecture abroad.”
Appellant Flynn alleged that:
“[She] desires to travel to countries of Europe and elsewhere for recreation and study, to observe social, political and economic conditions abroad, and thereafter to write, publish and lecture about her observations.”
The abridgment of liberty involved in this ease is more “drastic” than, and distinguishable from, that involved in American Communications Assn. v. Douds, 339 U. S. 382. In Douds the Court upheld § 9 (h) of the National Labor Relations Act as amended by the Taft-Hartley Act, 61 Stat. 136, 146, 29 U. S. C. § 159 (h), which conditions trade-union access to the facilities of the National Labor Relations Board upon the submission of non-Communist affidavits by officers of the union. Although the requirement undoubtedly discouraged unions from choosing officers with Communist affiliations, it did not prohibit their election and did not affect basic individual rights to work and to union membership.
In 1950 the Assistant to the Attorney General of the United States, Peyton Ford, expressed to Congress the views of the Department of Justice with regard to a proposed government loyalty bill which predicated a conclusive presumption of disloyalty on the fact of organizational membership. Mr. Ford said:
“A world of difference exists, from the standpoint of sound policy and constitutional validity, between making, as the bill would, membership in an organization designated by the Attorney General a felony, and recognizing such membership, as does the employee loyalty program under Executive Order 9835, as merely one piece of evidence pointing to possible disloyalty. The bill would brand the member of a listed organization a felon, no matter how innocent his membership ; the loyalty program enables the member to respond to charges against him and to show, in a manner consistent with American concepts of justice and fairness, that his membership is innocent and does not reflect upon his loyalty.
“. . . It does not appear, therefore, necessary, even if constitutionally possible, to add to existing law and regulations at the present time a penal statute such as proposed in the bill.
“The foregoing comments represent the considered views of this Department, having in mind that it is the duty of the Attorney General to protect the rights of individuals guaranteed by the Constitution, as well as to protect the Government from subversion.” Hearings on H. R. 3903 and H. R. 7595 before the House Committee on Un-American Activities, 81st Cong., 2d Sess., 2125.
The Government recognizes, however, that: “Membership, or even leadership, in the Communist Party is not automatically a crime.” Brief for Petitioner on Petition for a Writ of Certiorari, p. 11, United States v. Communist Party of the United States, No. 1027, O. T. 1963, cert. denied, 377 U. S. 968.
For appellants’ alleged purposes in traveling, see note 10, supra.
See Freund, The Supreme Court of the United States (1961), pp. 67-69; Note, 61 Harv. L. Rev. 1208 (1948); Note, 109 U. Pa. L. Rev. 67, 75-85 (1960).
Nor in our opinion should the Secretary of State or other government officers be exposed to the risk of criminal penalties for violating § 6 (b) by issuing a passport to a member of a registered Communist-action organization who is subsequently found by a court to be a person whose travel, contrary to the belief of the government officer, could constitutionally be prohibited.