With the reach that technology has in today’s connected world, everybody’s information is a mere Google search away in most instances. Personal information and data isn’t merely made available on social media websites either. There are reports of data breaches in various organizations on a near daily basis with dozens high-profile data thefts reported every year, while plenty more are certain to go unnoticed and not reported on.

Data theft is often undertaken by proficient and intelligent computer geniuses, with their primary motivations rooted in self-gaining profits at another’s expense. These malicious computer geniuses are popularly known as hackers. They’re also referred to as Black Hat hackers, cyber-criminals, or cyber-pirates. Not all hackers operate out of selfish intentions or greed, however. Some function purely out of curiosity to test the cyber security defenses of their targets.

In what is certain to make an intriguing list, here are the top 10 Black Hat hackers. (Those who got caught!)

Gary McKinnon, alias Solo

Not content with gazing at the stars, Gary McKinnon figured he’d directly gain access the computers of NASA. Infiltration was next on the agenda, as he hacked 97 NASA and US military computers by installing a malware virus and getting access. Not stopping there, he proceeded to remotely delete critical files that included weapon logs. While at it, he taunted the military, posting a banner on the website that read: “Your security system is crap. I am Solo. I will continue to disrupt at the highest levels.” Unfortunately for him, the hack was back-traced to his girlfriend’s aunt’s home in London. If all of that wasn’t enough, McKinnon took control of and shut down the U.S. Military’s Washington network that comprised of over 2000 computers, for a whole 24 hours. To this day, this has been the single biggest military computer hack of all time.

In 2006, he told Wired in an interview that he looked for files that contained evidence of extra-terrestrials during the NASA hack. In the interview, he alleges that he found them too (!).

Adrian Lamo, alias The Homeless Hacker

Adrian Lamo gained notoriety when he hacked a huge, multi-national, mainstream corporations such as Microsoft, Citi Group, Yahoo! And the New York Times. However, it was the way he went about the hacks that gained him the moniker as the “Homeless Hacker.” He gained the alias after he used public internet connections at libraries and coffee shops. He was caught in 2004 and after negotiated a plea bargain that mandated to him six months house arrest as well as being ordered by the court to pay $65,000 in restitution.

Mathew Bevan and Richard Pryce alias Kuji and Datastream Cowboy

This incident and hack may have proved to be the single most dangerous and damaging hack of all time. The year was 1994 when Mathew Bevan and Richard Pryce were 21 and 17 years of age. Breaking into military computers they nearly sparked a diplomatic incident when they hacked the Pentagon’s network for several weeks. If that wasn’t causing enough trouble already, they then proceeded to gain access to a Korean nuclear facility, using American computers.

There was respite, however, when the U.S. Government determined that the hack had targeted South Korea, instead of North Korea. If it had been North Korea, the implications of the hack could have been seen the triggering point to an act of war. Crisis averted. Matthew Bevan and Richard Pryce were arrested the following year.

Kevin Mitnick alias The Condor & The Darkside Hacker

Once known as the most wanted cyber-criminal in the U.S., Kevin Mitnick had hacked the networks of Nokia, IBM, Motorola and other big corporations in a two year spree. Millions of dollars in damages of corporate secrets and two prison sentences later, Kevin Mitnick is now a security consultant/hacker (of the good kind) and entrepreneur. Here’s a timeline of his hacking history:

After his first arrest in 1995, he was so notorious at the time that the judge ruling his case ordered him to solitary confinement, out of fears that he could spark a nuclear war (!) by whistling nuclear launch codes into a public payphone.

12 months of prison later, he didn’t give up hacking, continuing to do so even under supervised release that was mandated for 3 years.

When sentenced to prison again in 1999, he was the most wanted cyber-criminal in the U.S.

Albert Gonzalez alias SoupNazi, KingChill and CumbaJohnny

Albert founded the ShadowCrew forums and Shadowcrew.com and amassed nearly 4000 members at its peak. Stolen bank details, fake passports, social security cards, birth certificate, health insurance cards, and more were swapped and sold on the website. Originating from Florida, Gonzalez didn’t particularly keep a low profile, embracing an extravagant lifestyle. Expensive hotel stays were of the norm, while there were reports Gonzalez throwing a party that cost $75,000.

It’s estimated that over 170 million credit and debit card data were swapped on the ShadowCrew forums in two years from 2005 to 2007.

Here’s how Albert Gonzalez operated

At the time of his first arrest in New Jersey, Gonzalez was charged with possession of 15 fake bank cards in New Jersey. He avoided jail time however, after providing evidence about 19 other ShadowCrew members.

After returning to Miami, he hacked TJX (a company that owns several stores including T.J. Maxx), with 10 other members to form a hacking team. The theft resulted in the breach of 45 million credit and debit card numbers in just 18 months leading up to 2017.

Albert Gonzalez is currently serving a term in prison until 2015, after his arrest in 2008.

Vladimir Levin alias Unknown

Vladimir Leonidovitch Levin, a Russian hacker, along with three other hackers, siphoned off $ 10.7 million dollars from a select few corporate Citibank accounts from around the world. He did this while sitting and operating out of his apartment in St. Petersburg, Russia, in 1994.

Levin hacked these corporate accounts in Citibank using their wired, dial-up transfer channels to acquire account numbers and PINs to bypass security. Levin was caught in London by Scotland Yard officers and despite attempts to fight extradition to the U.S. by his lawyers, Levin was taken into American custody in September 1997.

Of the $ 10.7 million, Citibank claimed to have recovered merely $ 400,000. Levin was ordered by the court to pay $ 240,000 back to Citibank and was sentenced to 3 years in prison.

Kevin Poulsen alias Dark Dante

Kevin Poulsen will always hold the distinction of being the first American to be banned from using the Internet and computers.

Poulsen started by hacking phone lines during the early 90s and the late 80s. He rose to infamy after hacking the phone lines of Los Angeles radio station KIIS FM to be the 102nd caller in a contest. The prize? A Porsche. In a life that reads like that of an irreverent everyday hacker Joe, Poulsen went on the run when the FBI had set their sights on him. After he was caught, Poulsen served five years in prison and was subsequently banned from using computers and the internet for three years upon his release. These days, Poulsen works as a digital security journalist and a contributing editor at Wired.

Jeanson James Ancheta alias Resilient

Claiming yet another distinction, Ancheta from California was charged to be the first hacker caught in controlling botnets or groups of hijacked computers. He used these botnets to send large clusters of spam across the internet. In 2004, he used the worm “rxbot” to seize control of 500,000 computers (!) which included U.S. military computers. With such an army at his disposal, he then proceeded to put up banner advertisements for his services, offering those who are willing to pay the means to take down any website on the internet.

A year later, in 2005, one of the clients happened to be an FBI agent. Besides convicted to spend 5 years in prison, he was forced to turn in his BMW and pay $ 58,000 that was deemed to be earned during his hacking spree.

Owen Walker alias AKILL

Owen Walker was 17 years old when he led and marshalled an international network of hackers. This network infiltrated bank accounts to the tune of $20 million and also broke into some 1.3 million computers. At 13, Walker started learning programming and encryption with plenty of time on his hands while being homeschooled. For his part, Walker garnered $32,000 for writing the code that led to the hack carried out by other members in the network.

At 18, Owen Walker pleaded guilty and wasn’t convicted. He was ordered to pay back $ 11,000 and works as a security consultant.

Michael Calce alias Mafiaboy

A Canadian hacker, Michael Calce unleashed Project Rivolta (Italian for ‘riot’) to usher in the new millennium. The project was essentially a series of high profile denial of services attacks targeting eBay, Dell, CNN, Amazon and Yahoo!, which was at the time, the leading search engine ahead of Google. The attack led to Yahoo going down for an hour. President Clinton at the time, launched a cybersecurity task force tasked to apprehend ‘Mafiaboy.’

A year later, bragging in a chat room got Calce caught and he was sentenced to eight months of open custody with no jail time. A small fine and restricted use of the internet came with the conviction. Michael Calce was still a high-schooler at the time.

Michael Calce now works as a security consultant for several large corporations.

Many of these hackers managed to make quite a bit of money. Ultimately, however, almost all of them paid for their crimes with the most valuable thing in their life – their freedom. There is an upside, however. Several of these black-hat hackers have now become security consultants and experts that turned their attention to helping others with security-related matters.