Here's another reason to stay one from porn sites: they're bad for your computer's health. Ten percent of Britons' PCs havce picked up a virus after surfing adult sites.

That's according to a survey from comparison site Moneysupermarket, which also found that 19 percent of users have been infected through general surfing while 12 percent of users blamed opening files from unknown senders.

Moneysupermarket also revealed that of those infected by viruses. Five percent of respondents said personal information was stolen.

James Parker, manager of broadband at moneysupermarket, said: "People need to be more aware of security threats than ever before. Most people use some of their personal details online - whether through internet banking or online shopping - and it's vital that people take appropriate steps to protect this information and themselves".