Dave Buchwald (/ˈɑːrnɒk/; born September 4, 1970), is a filmmaker and former phone phreak, hacker, and leader of the Legion of Doom in the mid-1980s, then known as Bill From RNOC.

He was also known for hacking Bell and AT&T systems (specifically COSMOS, SCCS, and LMOS), which allowed him virtually unrestricted access to phone lines, including the ability to monitor conversations, throughout the United States.

In 1995, Dave was introduced to film making when he served as a technical consultant to the movie Hackers, editing the screenplay and personally coaching many members of the principal cast.

[citation needed] Buchwald works as a film editor, freelance photographer, and graphic designer in New York City.

[citation needed] In August 2018, Dave and his collaborator, Michael Lee Nirenberg, presented sample scenes from a documentary series they are producing, Reverse Engineering at the DEF CON annual hacking conference in Las Vegas.