10 Most Infamous Hackers Who Wreaked Havoc on the World

It’s a brave new world out there, folks, one where combat is waged increasingly in the digital space. While many of us live and work online, our encounters with the technological architecture on which our modern world is built are few and far between. Honestly, most of us would rather just ignore the machinery and pray that our day-to-day interactions go smoothly. We don’t really care about the inner workings too much as long things just work. Working with the Internet is a lot like owning a car in that respect. While most of us would prefer not to know too much about how these things work “under the hood” (just get me on Twitter and we can be friends, Internet), there are a select few people with the enthusiasm and the brainpower to weave their way through the foundations of our technological world. Most of these tech-savvy folks are simply there to learn and poke around, but some use this particular set of skills for nefarious purposes and their own personal gain. Here are ten of those infamous hackers who messed around with the computer infrastructure that the world depends on perhaps a little too much.

1. Owen Walker

Home-schooled from age 13 and armed with literally zero formal computer training, Owen Walker led a hacker collective that caused a reported $26 million in damages, including crashing the servers at the University of Pennsylvania. In spite of the fact that Walker plead guilty to the crime in 2008, the judge simply charged him for bringing down the University of Pennsylvania and let him walk without a conviction, saying that a conviction would irreparably damage the young man’s future. Soon after charges were dropped, Walker got a job teaching banks how to beef up their online security.

2. Michael Calce

For the uninitiated, a denial-of-service (or DoS) attack is what happens when a user barrages a server with a simultaneous pile of useless requests (millions and millions all at once), a workload that forces the server to simply shut down. In February of 2000, operating under the handle “Mafiaboy,” Michael Calce launched Project Rivolta (the Italian word for “riot”), a DoS attack that brought down the world’s biggest search engine (Yahoo!) for nearly an hour. Over the next week, Calce used similar tactics to take down eBay, CNN, Amazon, and Dell. Best of all, the only reason he was eventually caught is that he couldn’t help but brag about his victories online.

3. Kevin Poulsen

Poulsen has had perhaps the most successful post-hacking career of anyone on this list. During his time as a miscreant, he used his talent for largely silly purposes (like the time he rigged LA radio station KIIS-FM so he could win a Porsche). He was the first person in the world who was banned from using the Internet following his release from prison. After jail, Poulsen levied his talent and minor celebrity status into a job writing for Wired magazine, and has a lucrative career on the public speaking circuit.

4. Albert Gonzalez

Attending high school in Miami, Albert Gonzalez, the child of Cuban immigrants, was described by his classmates and teachers as the “troubled” ringleader of a group of self-described computer nerds. From 2005 to 2007, this “troubled” youth launched the most successful credit card fraud in human history. Over the course of two years, Gonzalez and his cohorts nicked more than 170 million credit card and ATM numbers using some back-end computer trickery. In 2010, Gonzalez was apprehended and sentenced to 20 years in federal prison.

5. Matthew Bevan and Richard Pryce

In 1996, Matthew Bevan and Richard Pryce very nearly kickstarted World War III. The duo, using the handles Kuji and Datastream Cowboy, respectively, hacked into a Korean base and began to dump the lot of Korean Atomic Research Institute’s database onto a United States Air Force system. At first, the USAF was terrified that these two jokers had hacked into a North Korean database. Thankfully, they were just poking around in a South Korean system, which is still bad, but not quite “act of war” bad.

6. Kevin Mitnick

In 1995, Mitnick was apprehended by the FBI in Raleigh, North Carolina. At the time, he was charged with 14 counts of wire fraud, 8 counts of “possession of unauthorized access devices,” and a truckload of hacking related crimes. In his possession, hundreds of cloned cellphone codes and dozens of fake IDs. Mitnick had been on the run from authorities for two-and-a-half years at that point. He’s suspected to have gained unlawful access to dozens of computer systems (one of which was Pacific Bell), going back to the tender age of 13, when he figured out a way to ride every city bus in LA for free.

7. Vladimir Levin

In 1994, Russian-born system administrator Vladimir Levin paid $100 for details on system access deep inside Citibank’s network. These access routes had been cultivated by a group who intended to test their ability before ceasing to use the network. Once Levin paid for access, though, he and six others transferred $10.7 million of Citibank’s money to accounts around the globe. The bank (shockingly) took notice and launched a worldwide manhunt for Levin, eventually nabbing him in London in 1995. He was sentenced to three years in jail and a fine of $240 grand. Here’s the kicker, though: about $400,000 of the stolen money has never been recovered, meaning Levin — or someone close to him — may have gotten some kind of pay day after all.

8. Jacob Applebaum

Jacob Applebaum was one of a handful of computer savvy individuals to have gotten firsthand access to Edward Snowden’s leaked files. His connections (to WikiLeaks founder Julian Assange as well as Snowden) and public activism have made him the consistent target of the U.S. government. In 2010, for example, they considered this guy such a threat that they forced Twitter to submit his account data.

9. Astra

Astra’s identity has never been publicly revealed … most likely because he’s now buried under some Greek jail in the country’s one dark corner. This anonymous hacker stole more than $350 million in secrets from an Greek aircraft company named Dassault. Astra, a 58-year-old mathematician went on the run in 2002, eluding authorities for six years before he was tracked down in an Athens apartment where he was living under an assumed name.

10. Anonymous

Depending on who you ask, Anonymous is either a phantom scourge or a loose collection of freedom fighters. While they began around 2003 as a disorganized collection of people just out for a laugh, the group quickly transitioned into a more ominous but progressive version of themselves. Today, they are known to disrupt sites and pilfer communications from any group they deem in need of some humbling. The NYSE, the MPAA, Israel, a revenge porn site, Westboro Baptist Church, ISIS, the KKK, the list of Anonymous’ targets goes on and on and on. You can’t deny the talent of this collective, whether you agree with their politics or not. And — if you do disagree with them — it’s probably best to keep it to yourself.