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)
Fax demodulator Fax demodulator A fax demodulator is a device used to intercept fax messages by listening in on a telephone line or radio signal. A typical (Group III) fax transmission requires a two-way conversation between two modems (that is, each participant must both transmit and receive). Each modem may be part of a “fax machine” incorporating an image scanner and a printer. A demodulator can only be used to observe a conversation between two fax modems, usually to record the image transmitted. It cannot be used to receive a fax transmission in the usual sense, because a sending modem cannot transmit