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 send. The document is usually converted to PDF or TIFF format and sent by the Web server to the fax server, which then transmits it to the receiving fax machine via the telephone network. The sender usually receives confirmation that transmission was successful, either in the web interface or by email. An Internet fax service allows faxes to be sent from a computer via an Internet connection, thanks to a Web interface usually available on the supplier's Web site. This technology has many advantages: Early email-to-fax services such as The Phone Company and Digital Chicken were developed in the mid-1990s.