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)
Internet fax a phone number, and press a button. Fax continues to be used over the telephone network at locations without computer and Internet facilities; and sometimes a fax of a document with a person's handwritten signature is a requirement for legal reasons. Computer fax over the Internet allows fax communication without an actual fax machine at either or both ends. The traditional method for sending faxes over phone lines (PSTN) A fax machine is an electronic instrument composed of a scanner, a modem, and a printer. It transmits data in the form of pulses via a telephone line to a recipient,