2600

The number 2600 “has special significance to the hacker community. It is the hertz frequency. . . of a signal that some hackers formerly used to explore the entire telephone system from ‘operator mode,’ which was triggered by the transmission of a 2600 hertz tone across a telephone line, or to place telephone calls without incurring long-distance toll charges. One such user reportedly discovered that the sound of a toy whistle from a box of Cap’n Crunch cereal matched the telephone company’s 2600 hertz tone perfectly.”