Black fax to harass large institutions or government departments, to retaliate against the senders of junk faxes, or merely as simple pranks. The basic principle of a black fax can be extended to form a "black fax attack." In this case, one or more sheets are fed halfway through the sender's fax machine and taped end to end, forming an endless loop that cycles through the machine. Not only can solid black be used, but also images which will repeat endlessly on the receiver's machine until its toner runs out. The introduction of computer-based facsimile systems (combined with integrated document imaging solutions)
Junk fax transmitting organization or individual on each page. The process of war dialing to determine what phone numbers reach fax machines was also prohibited by the FCC rules under the TCPA. The TCPA, in particular the junk fax provision, has been challenged in court on First Amendment grounds, but the law has withstood legal challenges. In 2005, the United States Congress passed the Junk Fax Prevention Act of 2005. It amended the TCPA so as to no longer prohibit unsolicited fax advertisements if: and the sender complies with other requirements. In April 2006, the Federal Communications Commission (FCC) implemented changes to