IT security and data protection firm, Sophos, is today warning Facebook users to be wary of bogus event invites that are currently circulating on the social network. Spammers have invited millions of Facebook users to fake events in an attempt to generate income from online survey scams.

One event, called "Who blocked you from his friend list?" has already tricked more than 165,000 people into signing-up, with a staggering 10.3 million users still debating whether to respond or not.

The scammers embed instructions into the 'More info' section of the event's summary, which leads unsuspecting Facebook users into visiting webpage's for online surveys or competitions, designed to earn commission for those behind the scheme. In some instances, users are also asked for a mobile phone number - which is then signed up to an expensive premium rate service.

"These spammed-out event invitations and links to survey scams are one of the biggest nuisances on Facebook right now, impacting millions of users every day," said Graham Cluley, Senior Technology Consultant at Sophos. "It would be great if Facebook was being more proactive in shutting down these obviously bogus events, as currently it's far too easy for the scammers to fill their pockets through schemes like this."

Facebook users are reminded never to accept unsolicited invitations from suspicious events, and always think twice about clicking on links received via Facebook.