Most of the things we call hacking are no such thing: they're the result of off-the-shelf malware toolkits that even your gran could use.

But that wasn't always the case.

Audacious hackers have scared the military, cheated competitions, brought down thousands of websites and defrauded giant banks - and some of them have never been caught.

Here, in reverse order, are the ten most outrageous hacks of all time...

10. Britney's Twitter
Last week, celebrities posted strange things to Twitter. Britney Spears informed the world that her bits had teeth [Language NSFW]; Fox News announced that right-wing news monster Bill O'Reilly was gay; and even Barack Obama's account was compromised. It turns out that some 33 accounts had been hacked by an as yet unidentified ruffian.

9. Site seeing
Defacing a website isn't that difficult; defacing several is only a little bit harder. Defacing 90,000 sites over two years, though, is pretty impressive. That's the tally racked up by Turkish hacker Iskorpitx during 2004 and 2005.

8. Palin's privacy
You'd think that a vice-presidential candidate would use something a bit more secure than Yahoo! Mail for their messages. Nope. Inevitably somebody found a way in - an anonymous user from the home of online mischief-making, 4Chan - and posted the logins for other 4Chan users to have fun with. Yahoo! spotted the unusual activity and froze the account, but not before the emails had been leaked to the media.

7. Dante's infernal
Now a senior editor at Wired News, Kevin Lee Poulsen appeared in the tech press for very different reasons during the 1980s. As notorious cracker Dark Dante he had a knack for publicity-generating stunts, such as hacking the phone system of an LA radio station so he would win a Porsche. Poulsen was arrested in 1991 and sentenced three years later, receiving the longest sentence ever handed out for hacking: 51 months in prison and a $56,000 fine.

6. Trial by Hollywood
Kevin Mitnick has an unusual claim to fame: he's the only hacker to have been found guilty by movie-makers while his real-life trial was still under way. Mitnick broke into his first computer system in 1979, and 20 years later he pleaded guilty to multiple charges of illegally accessing networks and acquiring copies of software, resulting in a five-year sentence including eight months in solitary confinement. He accessed so many systems there's an entire Wikipedia page listing his exploits. Mitnick didn't use software; rather, he used social engineering to trick people into giving him the logins he needed.

5. Space oddity
Jonathan James was the first juvenile ever jailed for cyber-crime in the USA. He was caught in 1999 after he accessed military and NASA systems, getting hold of source code for part of the International Space Station. It wasn't long before the Feds came a-knocking, and 16-year-old James was sentenced to six months imprisonment and put on probation until he was 18.

4. Windows pains
The source code for Windows is more closely guarded than Colonel Sanders' secret blend of spices, but hackers still managed to grab the code for Windows 2000 and NT in 2004. The culprits were never caught.

3. Maxx out those credit cards
When it comes to ID theft, Ukranian Maksym Yastremskiy is an expert: his gang stole 45 million identities from US retailers including TK Maxx's parent company, TJX. The gang took advantage of unprotected wireless networks to grab card details they could use in cash machines, but Yastremskiy was caught - and sentenced to 30 years in prison.

2. Bank jobs, cyber style
In 1998, Vladimir Levin was sentenced to three years in jail and fined more than $240,000 for his part in a plot to defraud Citibank of nearly $10.7 million. Levin was accused of masterminding the plot, in which the gang accessed the accounts of Citibank corporate customers via the bank's dial-up banking system, although in 2005 a man claiming to be one of the hacking group claimed that Levin was a mere systems administrator who had been offered the customers' logins for a small sum. For its part, Citibank says that all but $400,000 of the missing money has been recovered.

1. Guantanamo for Gary?
You don't get much more outrageous than perpetrating "the biggest military computer hack of all time". Scots hacker Gary McKinnon is accused of just that, and the US wants to extradite him so he can face up to 45 years in jail. McKinnon is accused of hacking into some 97 different systems including NASA and US military computers during 2001 and 2002. He says he was looking for evidence of UFOs; the US authorities say he caused hundreds of thousands of dollars worth of damage. Gary's next judicial hearing is on 20th January.