Peiter C. Zatko, better known as Mudge, is an American network security expert, open source programmer, writer, and a hacker. He was the most prominent member of the high-profile hacker think tank the L0pht as well as the computer and culture hacking cooperative the Cult of the Dead Cow. In 2010 Mudge accepted a position as a program manager at DARPA where he oversaw cyber security research. In 2013 Mudge went to work for Google in their Advanced Technology & Projects division. In 2020, he was hired as head of security at Twitter.