Hundreds of thousands of Facebook users have been fooled into spreading unwanted code in a new social networking cheat known as 'likejacking' or 'clickjacking'.

Promising images of naked celebrities, details of Justin Bieber's  hacked phone or information about the BP oil spill, the scam operates by requesting users 'click here to continue if you are 18 years of age or older'. Any click made however will be hijacked, forcing the 'like' function to operate, which in turn publishes a 'like' notice on the user's profile. The link is then shared among friends and spreads virally.

Users are being warned that other fronts for the exploit include pages that offer details about the new Shrek film, intriguing page descriptions such as 'This man takes a picture of himself EVERYDAY for 8 YEARS!' and a fake HD plugin for fans of the World Cup.