Joybubbles hashtag Josef Carl Engressia Jr., aka: Whistler, later known as Joybubbles, was a blind phone phreaker with the extraordinary gift of absolute pitch. He could whistle a perfect 2600 Hz tone, the exact frequency needed to manipulate AT&T’s phone system. Without using any devices, he could seize control of long-distance calls just by whistling into the handset. In 1971, Engressia became the first phreaker to face legal consequences when he was arrested and fined twenty-five dollars for phone fraud. Despite this, he remained a legendary figure in phreaking culture. Later in life, he legally changed his name to Joybubbles. #Phreaking #2600Hz #Joybubbles #PhoneHacking #HackerHistory