Mark Abene (born 1972), is an infosec expert and entrepreneur, originally from New York City. Better known by his pseudonym Phiber Optik, he was once a member of the hacker groups Legion of Doom and Masters of Deception.Phiber Optik was a high-profile hacker in the 1980s and early 1990s, appearing in The New York Times, Harper's, Esquire, in debates and on television. He is an important figure in the 1995 non-fiction book Masters of Deception — The Gang that Ruled Cyberspace.
Mark Abene was one of the most skilled computer hackers of the late 1980s and early 1990s. He used his abilities to study how computers and phone systems worked, not for his personal financial gain or to destroy information. Nowadays Abene is a consultant to various companies to help strengthen their data security.