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 in the number of fax machines in the U.S. The invention of the computer-based fax board in 1985 by Dr. Hank Magnuski, provided an efficient platform for reaching those fax machines with minimal cost and effort. The fax machines of this period typically used expensive thermal paper and a common complaint about junk faxes was that they consumed that expensive paper without permission, thus shifting the cost of printing the advertisement to the recipient. In the U.S., the passage of the Telephone Consumer Protection Act in 1991 along with action by individual states reduced the use of junk faxes at