It's a day for scams. Think you've been given the chance to sign up as an iPad tester via Facebook? No you haven't - it's a scam which actually signs you up to a premium rate mobile service, warns the security company Sophos.

"Facebook pages with names such as "iPad Researchers Wanted - Get An iPad Early And Keep It!" and "The Mega iPad Giveaway!" prey on the public's desire to own a free iPad," notes Sophos.