Hackers are computer experts who seek out and exploit weaknesses in a computer system. Hackers may seek out these vulnerabilities in order to improve the security of the system, or they may simply use their knowledge of back doors for their own financial gain. As technology has become more widespread, hackers have gained more and more power. Early hackers had limited ways to game the system, with some of the most notable early hacks revolving around loopholes in the long distance phone system. As technology has evolved, hackers have developed increasingly complex methods for stealing data or cash. Today's hackers have the power to steal our personal data through compromised USB sticks, smartphones, or even airplane Wi-Fi systems. While some hacker groups (white hats) claim to have the greater good in mind, other groups (black hats) are clearly driven by greed. There have been dozens of movies about hacker culture over the years. Some films glorify white hats, while others feature the escapades of notorious black hats. Some of the most famous films about hacking include Hackers, Swordfish, WarGames, and the upcoming film Blackhat, starring Chris Hemsworth. While some movies about hacking aren't terribly realistic, they have done a lot to raise public awareness about hackers, cyberterrorism, and cybersecurity. Throughout the years, there have been a few elite groups of hackers that have caused major disruptions. These groups have stolen money, crippled websites, and made headlines all over the globe. Here are five of the most powerful groups of hackers in recent memory. Read on to learn more about these powerful groups.