Anonymous

While not a single person, “Anonymous” might be the most well-known hacker group in the world. You’ve probably seen the Guy Fawkes mask that some members of the community wear, inspired by the movie V for Vendetta.

Most Known For: In 2011, Anonymous took down the PlayStation Network for an entire month as retaliation for Sony trying to stop PlayStation 3 hacks. More than 100 million Sony accounts were compromised in the process.

Kevin Mitnick

Kevin Mitnick is an American hacker who got his start as a teen. At age 16, he broke into Digital Equipment Corporation’s (DEC) computer network and copied the company’s software. He was later convicted for the crime at age 25.

While he was a fugitive for two and a half years, Mitnick hacked dozens of computer networks. One of his favorite tactics was to clone cell phones to hide his location and then copy highly-protected proprietary software from the carriers and computer companies.

Most Known For: Maybe not the biggest hack, but one of Mitnick’s hacks was the inspiration for a movie. The 1983 film War Games was inspired by his hack of NORAD in 1982. He was only 17.

Edward Snowden

Technically speaking, Edward Snowden isn’t a “hacker.” He used his privileges as a system administrator for the NSA to leak 20,000 highly classified documents that revealed numerous global surveillance programs.

Snowden was able to gain access to these documents without leaving a trace. The NSA was not monitoring the system for leaks, and Snowden took advantage of that lax security. He simply put the files on a USB drive and took them with him.

Most Known For: Snowden’s leaking of NSA documents has had a lasting impact on public opinion about government surveillance. Many people had no idea about the NSA’s domestic internet surveillance before Snowden’s massive leak (despite the existence of things like Room 641A being previously reported.)

Julian Assange

Julian Assange started hacking when he was 16 under the name “Mendax.” In those early days, he was able to gain access to major networks from the likes of NASA, Lockheed Martin, and the Pentagon.

However, Assange is most well-known for creating WikiLeaks in 2006. WikiLeaks was a platform for publishing classified documents from anonymous (not that Anonymous) sources. One of the biggest sources was Chelsea Manning, a U.S. Army intelligence analyst.

Most Known For: WikiLeaks claimed in 2015 that it had released 10 million documents since it started in 2006. Many of these documents revealed major human rights violations to the U.S. and international public.

Adrian Lamo

Adrian Lamo was a hacker known as the “Homeless Hacker.” He got the nickname by hacking companies from his laptop at coffee shops, libraries, and other remote locations.

Some of the high-profile companies he hacked include Google, Microsoft, The New York Times, and Yahoo. When he hacked The NYT in 2002, he added himself to the network’s list of expert sources and used the LexisNexis account to conduct research on high-profile subjects.

Most Known For: Lamo was eventually arrested and worked with the U.S. government as a threat analyst. He’s perhaps most known for turning in Chelsea Manning as a source for WikiLeaks documents.

Hackers are not inherently bad or good; it depends on the intentions of the person (or group) doing the hacking. Edward Snowden, for example, is highly controversial and has been called both a hero for pulling back the curtain on the NSA and a traitor for revealing that same information. Wherever there are highly-secured systems, there will be hackers trying to get into them.

RELATED: Why “Hackers” and “Hacks” Aren’t Always Bad