But not all of them are criminals, and more and more companies hire so-called "white hat" hackers to get into their security systems and show them where their weaknesses are, paying them for every "mistake."
In fact, large companies can be very generous if someone discovers a bug in their codes.
Proof of this is that Apple has recently offered a $ 1 million reward to anyone who can access an iPhone using a specific hacking method.
Business Insider has exchanged several emails with two young hackers who became millionaires after they discovered several vulnerabilities in different companies.
Santiago López lives with his parents and became the first bug bounty millionaire (which in Spanish translates as 'Internet bounty hunter' or 'white hat hacker')
Santiago López, 19, currently lives with his parents in Buenos Aires. In February he officially became the first bug bounty millionaire, according to HackerOne.
Lopez told Business Insider that he started in this sector at age 15, and earned his first reward for discovering vulnerabilities at 16. He earned $ 50. Until he was hired at HackerOne he didn't think he could do it professionally.
"I realized how much money I could earn through ethical hacking. The platform made me aware of several leading organizations that pay very well for vulnerabilities, so I had the opportunity to earn a small fortune and make a professional career with hunting of online rewards, "he said.
Lopez has managed to become a millionaire through HackerOne's private proposals, instead of searching daily for public bug reward programs.
"I usually spend six or seven hours a day hacking, so it's almost like a full-time job," he said. "When you find a computer error, it is the best feeling in the world."
Santiago has saved enough money to buy 2 cars (a Peugeot RCZ and a Mini Cooper) and a beach house.
"I will always want to hack, since I really enjoy the challenge, but I would like to go to college at some point and start studying. After that, I would like to start my own company in the security sector," he said.
"Hacking will always be a big part of my life," he added.
Nathaniel, "Naffy" Wakelam, started hacking as a student
Nathaniel Wakelam was born in Australia, is 24 years old and is the IT Security director of a consulting firm. His friends call him Naffy, and he has recently settled in Thailand.
Like Lopez, Wakelam got into hacking as a teenager - he spent most of his time hacking a video game to give himself an unfair advantage. "I found vulnerabilities in the game that allowed me to become invisible ... double my earnings online and move to restricted map areas," he told Business Insider. Although he preferred not to say its title, he did confirm that it was a great MMO (Massively Multiplayer Online game or massively multiplayer online role-playing game, for its translation into Spanish). Among the most popular is "World of Warcraft".
"I later discovered that what I was doing was very similar to what I am currently doing," he said.
First he dedicated himself to hacking to solve his financial problems. "During my first semester at the university I had trouble paying the rent. I also worked 5 hours a day for 5 days a week as a telemarketer," he said.
"After doing this for a month, I realized that it was unsustainable. At the same time, Yahoo had just created its bug rewards program. I earned $ 60,000 quickly, so I decided to devote myself to it full time."
Today, Wakelam works with Riot Games, the game studio behind the popular game "League of Legends," and Verizon.
Unlike Santiago, Wakelam's schedule is not fixed. "When I don't find many computer errors I can dedicate only 5 hours a week, but when I do well they can be 30 to 40 hours," he said.
Wakelam also said he can't imagine a future for himself without hacking. "After working as a consultant and in the bug rewards business for many years, I have diversified and created a computer security consultancy called Gravity. The new challenges and experiences I have in this sector year after year keep me interested, and I don't see myself doing anything else, "he said.