Computers are now getting humans to do their dirty work -- by offering them smutty pictures!

For years many websites have used the CAPTCHA ("Completely Automated Public Turing test to tell Computers and Humans Apart") system to prevent the automated creation of things like email accounts that can then be used by spammers. You've almost certainly encountered these things; boxes of wobbly text like the one at the head of this column that you have to correctly interpret in order to authorise the account. Humans have no problem with this sort of thing but computers find it almost impossible.

Now scammers have come up with a clever little workaround. Websites have appeared showing pictures of scantily clad women who strip off more and more layers provided you correctly enter the CAPTCHA string displayed. But what you don't realise is that those CAPTCHA graphics are being relayed from sites like Yahoo! Mail and Gmail where an automated process is setting up bogus accounts and using your brain power to help out!

It's naughty, of course, but also kind of neat. And it shows once again no matter how sophisticated security systems get, there are often simple ways to work around them.