need to know : Top 5 Hackers

The more we rely on technology, the more power hackers potentially have over us.

Whether their intention is to help or to harm, hackers have the power (like it or not) to change the world.

They may inspire fear, but over the years, we've learned a lot from their snooping and stealing.

No. 1 - Robert Tappan Morris

Even if you know next to nothing about computer viruses, you've probably heard of "worms." That's because news stories about this particularly contagious (and therefore destructive) breed of virus abound.

Blame Robert Tappan Morris for it all.

Back in 1988, while a graduate student at Cornell University, Morris created the first worm and released it on the Internet. He claimed it was all an experiment gone awry, a test to see how big the then-new Internet was. The worm turned out to be more than a test: it replicated quickly, slowing computers to the point of non-functionality and virtually crippling the Internet. He was eventually fined and sentenced to three years probation.

Since then, he's earned his Ph.D. from Harvard and made millions designing software. Today, he's a computer science professor at MIT. Not bad.

No. 2 - Kevin Mitnick

Kevin Mitnick started out just wanting a free ride on the bus.

He came a long way from his hacks into the Los Angeles metropolitan bus system and early dabbling in phone fraud. Mitnick went on to become the most wanted computer hacker in the country, known (and wanted) primarily for his hack into Digital Equipment Corporation's network to steal their software.It may have been his first notable break-in, but Mitnick went on to other big targets, including cell phone giants Nokia and Motorola.

Even his eventual arrest was notable: After hacking into fellow hacker Tsutomu Shimomura's computer, Mitnick was tracked down by Shimomura and the FBI in 1995.

Today, Mitnick has served a five-year sentence and come clean, but he continues to profit off his former title, authoring books and working as a security consultant.

No. 3 - Adrian Lamo

It's true that companies sometimes hire hackers to test their systems for weaknesses, but no one ever hired Adrian Lamo.

In 2002 and 2003, Lamo broke into several high-profile targets, just for kicks. He then told the targets what he had been able to do and how he did it. How kind of him. Lamo's targets included Microsoft, Yahoo and the New York Times, where he inserted his contact info into their database of experts.

Known as "the homeless hacker," Lamo slept in abandoned buildings and hacked via laptop from Internet cafes and public libraries. His network-busting technique of choice involved going in through the out door, entering sites through proxy access, a setup that corporations often use to let their computers connect out to the Internet. That led to his arrest in 2003.

Lamo served two years probation and now works as a tech journalist.

No. 4 - Gary McKinnon (aka Solo)

Scottish-born, London-based hacker McKinnon wasn't just in it for fun; he had a political axe to grind.

Conspiracy-theorist McKinnon broke into computers at the U.S. Department of Defense, Army, Navy, Air Force and NASA sometime in 2001 and 2002. What exactly was he looking for? Evidence of really fuel-efficient alien spacecraft, for one.

No joke.

McKinnon believes the U.S. government was hiding alien technology that could solve the global energy crisis. Now, in the process of snooping around for this stuff, the self-taught hacker concedes he may have deleted a whole bunch of other files and maybe some hard drives as he attempted to cover up his tracks. Nothing significant, he insists.

The U.S. government begs to differ, claiming McKinnon's hack job cost them &36;700,000 to fix. They also kind of doubt the whole UFO story and wonder if his snooping had more earthly intentions. Back in the U.K., Gary's lawyers insist that their client, who suffers from Asperger's Syndrome, deserves special mental health considerations.

Gary himself has become a cause celebre, with his pending extradition being protested by celebrities like Sting.

No. 5 - Raphael Gray (aka Curador)

Raphael Gray called himself a saint, insisting he was only trying to help e-commerce sites when he broke into their databases to steal credit card numbers and personal information from 26,000 or so American, British and Canadian customers in 2000.

The then-18-year-old Welsh teenager insisted he was merely trying to draw attention to lax online security systems. So, if he was really just trying to help, then why did he post the card numbers online? Well, that's another question.

Gray was sentenced in 2001 to three years of psychiatric treatment.