Greg Hoglund
American researcher who turned Windows rootkits into a public field of study, and whose company later became Anonymous's most famous scalp.
In 1999 Hoglund published one of the first Windows NT rootkits in Phrack and launched rootkit.com, a forum where techniques for hiding code in the kernel were discussed in the open, on the theory that defenders cannot detect what they do not understand. He co-wrote Exploiting Software (2004) with Gary McGraw and the standard text Rootkits: Subverting the Windows Kernel (2005) with Jamie Butler.
In 2003 he founded HBGary, which sold memory forensics. In February 2011 the head of its sister company HBGary Federal claimed to have identified Anonymous's leadership. The response arrived within a day: emails leaked, websites defaced and the rootkit.com user database dumped. An expensive lesson in not provoking your research subjects.