Bill Cheswick is an early innovator in Internet security. He is known for his work in firewalls, proxies, and Internet mapping at Bell Labs and Lumeta Corp. He is best known for the book he co-authored with Steve Bellovin and now Avi Rubin, Firewalls and Internet Security: Repelling the Wily Hacker. He is now a member of the technical staff at AT&T Labs Research in Florham Park, New Jersey, where he is working on security, visualization, user interfaces, and a variety of other things.