Facebook stepping up battle against spammers who sell fake 'likes'

Facebook has revealed it has stepped up its battle against spammers who promise to deliver thousands of "likes" in return for money and warned users to beware of such scams.

The world's most popular social network said that to date, it had obtained legal judgments of nearly US$2 billion against fraudulent activities on Facebook. It was not clear how much of the amount was actually collected.

Facebook's moves appeared to counter concerns that users, including politicians and companies selling products, are buying "likes" to make them appear more popular.

And it is targeting this cottage industry, which seeks to deliver these results to Facebook members, often promising "10,000 likes" or more for a fee.

"We write rules and use machine learning to catch suspicious behaviour that sticks out. When we catch fraudulent activity, we work to counter and prevent it, including blocking accounts and removing fake likes all at once," Facebook site integrity engineer Matt Jones said in a blog post.

"As our tools have become more sophisticated, we've contributed some of our spam-fighting technology to the academic community as well, in hopes of helping other companies combat similar problems."