They can swipe military secrets from miles away, bypass steel doors with a single click, and break into your bank account without breaking a sweat. Magicians? Supervillains? No — hackers!

Since the world went online, tech-savvy people have been taking advantage of the web's twists and turns to get rich and get powerful — or just to see how much of a mess they can make. We combed through the internet's history and found nine hackers who had huge impacts. Read on to see who did the most damage — and then maybe change your wireless password, just in case.