Hackers mostly exist outside the public consciousness—just doing their thing and lying low.

Let’s take a look at five infamous hackers.

Anonymous started in 2003 in4chan, and it has attacked numerous big-name targets since.

Photo from the movie

Metro-Goldwyn-Mayer Studios

Some of those include Amazon, the Church of Scientology, PayPal, and multiple governments around the world.

Dozens of people have been arrested for their involvement with the group.

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.

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.

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.”

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.

Julian Assange

Julian Assange started hacking when he was 16 under the name “Mendax.”

However, Assange is most well-known for creatingWikiLeaksin 2006.

WikiLeaks was a platform for publishing classified documents from anonymous (not that Anonymous) sources.

One of the biggest sources wasChelsea Manning, a U.S. Army intelligence analyst.

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.”

Some of the high-profile companies he hacked include Google, Microsoft, The New York Times, and Yahoo.

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.

Wherever there are highly-secured systems, there will behackers trying to get into them.

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