a device into the package to notify them when the package was opened. 4 . Although not relevant here, it is worth noting that there is a remaining question — unresolved in the Supreme Court and the Fourth Circuit — concerning whether letter mail is an exception to the general rule that border searches are per se constitutionally reasonable. Although the Supreme Court and the Fourth Circuit have acknowledged the question, both have thus far declined to decide it. See Ramsey, 431 U.S. at 611, 97 S.Ct. 1972 (declining to reach this question because the search in issue was justified by reasonable cause to suspect the unlawful importation of contraband); United States v. Safari, 849 F.2d 891 (4th Cir.1988) (same). 5 . See also United States v. Bilir, 592 F.2d 735, 740 (4th Cir.1979) (<HOLDING>). 6 . Section 1581 authorizes "[a]ny officer of
holding that seven hours was a reasonable amount of time to deliberate meaningfully about the choice recognizing the search of incoming international mail at or near the arrival airport to be a search at the functional equivalent of the border holding that a search less four miles from the border was a border search where the vehicle was searched seven hours after crossing the united states border from mexico but continuously surveilled during those seven hours holding that plaintiffs had standing to challenge stops by the united states border patrol because plaintiffs could be stopped without engaging in illegal conduct holding that delay of several hours after the vehicle was seized was reasonable