Anonymous, a group of hackers originating in 2003.
LulzSec, a group of hackers originating and disbanding in 2011 that claimed to hack "for the lulz".
Chaos Computer Club, is based in Germany and other German-speaking countries and currently has over 9,000 members.
Legion of Doom, a hacker group active from the 1980s to the late 1990s and early 2000.
Masters of Deception, initial membership grew from meetings on Loop-Around Test Lines that led to legendary collaborations to hack RBOC phone switches and the various minicomputers and mainframes used to administer the telephone network.
w00w00, is currently one of the largest non-profit security teams in the world with more than 30 active participants.
TESO, was a famous hacker group, which originated in Austria and quickly became international. It was active from 1998 to 2004, and during its peak around 2000, it was responsible for a significant share of the exploits on the bugtraq mailing list.
L0pht, was a hacker collective active between 1992 and 2000 and located in the Boston, Massachusetts area.
Cult of the Dead Cow, also known as cDc or cDc Communications, is a computer hacker and DIY media organisation founded in 1984 in Lubbock, Texas.
milw0rm is a group of "hacktivists" best known for penetrating the computers of the Bhabha Atomic Research Centre (BARC) in Mumbai.
TeaMp0isoN is a group of Black-Hat Computer Hackers established in mid-2009
Decocidio is an anonymous, autonomous collective of hacktivists which is part of Earth First!!, a radical environmental protest organisation, and adheres to Climate Justice Action
Goatse Security (GoatSec) is a loose-knit, nine-person grey hat hacker group that specializes in uncovering security flaws.
Global kos were a grey hat (leaning black hat) computer hacker group active from 1996 through 2000.
globalHell was a group of hackers, composed of about 60 individuals. The group disbanded in 1999, when 12 members were prosecuted for computer intrusion and 30 for lesser offences.
Hackweiser is an underground hacking group and hacking magazine founded in 1999.
Honker Union is a group known for hacktivism, mainly present in Mainland China, whose members launched a series of attacks on websites in the United States, mostly government-related sites.
Level Seven was a hacking group during the mid to late 90's. Eventually dispersing in early 2000 when nominal head 'vent' was raided by the FBI on February 25, 2000.
NCPH is a Chinese hacker group based out of Zigong in Sichuan Province. While the group first gained notoriety after hacking 40% of the hacker association websites in China, their attacks grew in sophistication and notoriety through 2006 and received international media attention in early 2007