Facebook strips smiles from fake 'like' sellers

Advances in technology for recognizing suspicious patterns of likes has enabled the social network to block such activity by malicious software, fraudulent accounts, and click farm operations that employ armies of low-paid workers.

"We continue to adapt and improve the methods we use to prevent fake likes because scammers are constantly evolving and testing new methods to try to get around our spam prevention systems," Facebook site security engineer H. Kerem Cevahir said in a blog post.

"This work has made it extremely difficult for the people selling fraudulent likes to actually deliver their promised likes to paying customers."

During the past six months, Facebook has tripled the number of seemingly bogus likes detected and blocked before reaching pages, according to Cevahir.

He credited the campaign with causing a large number of vendors hawking inauthentic likes to go out of business.

Facebook also removes fake likes from pages at the social network, notifying account administrators to the actions.

Cevahir said that fraudulent behavior was only "a tiny fraction" of the overall activity on Facebook.

"Likes created by fake accounts or people without real intent are bad for people on Facebook, advertisers and Facebook itself," read a security guidance page at California-based online social network.