Engressia, who was born blind and died at age 58, happened to have perfect pitch and learned how to recreate the touch-tones necessary to move the switches at AT&T in the 1970s. Using this technique, he led a movement of hackers who reveled in tinkering with the telecommunications giant's system.

The obit is a fascinating read. It includes a number of interesting details about Engressia's life, including the fact that in 1988 he chose to "remain 5 forever, and had the toys and teddy bears to prove it."

A 1971 Esquire magazine article called Joybubbles a catalyst uniting disparate phreaks. "Every night he sits like a sightless spider in his little apartment receiving messages from every tendril of its web," the article's author wrote.

Engressia moved to Minneapolis on June 12, 1982, partly because that date’s numerical representation of 6-12 is the same as the city’s area code, the Times reported. There, he lived on Social Security disability payments and part-time jobs "like letting university agriculture researchers use his superb sense of smell to investigate how to control the odor of hog excrement."

Read more about Joybubbles on Wikipedia.