According to independent research conducted on Facebook's alleged activities on private messages, a lawsuit claims the social networking giant collates messages "for purposes unrelated to the facilitation of message transmission."

"Representing to users that the content of Facebook messages is "private" creates an especially profitable opportunity for Facebook," the lawsuit reads.

Essentially, the allegation states that the big name social networking provider is using links from private messages to bump up the number of 'likes' on Facebook. When the links are recorded, it would increase a brand's Facebook activity even without revealing private information. In a nutshell, this would increase the number of like for a particular firm with a presence on Facebook.

Mark Zuckerburg, founder of Facebook and the rest of his team said it would defend the class-action lawsuit 'vigorously' and that the case in question is 'without merit.'

A Zdnet report said, "Contrary to its representations, "private" Facebook messages are systematically intercepted by the Company in an effort to learn the contents of the users' communications [..] This practice enables Facebook to mine user data and profit from those data by sharing them with third parties -- namely, advertisers, marketers, and other data aggregators.".

Security expert, Graham Cluley was quoted by BBC as saying, Facebook reveals failure of 'duty of care' if it does not check links in private messages. The idea being each message could carry phishing attacks, scams, spams and whole bunch of other stuff.

This is not the first time Facebook has been criticized over data use. In September, the company said it would use Facebook user data such as names and profile photos in ads and this was another point of debate for users.

The litigation was brought forward by Matt Campbell, an Arkansas lawyer and Michael Hurley of Oregon at the U.S. District Court, Northern California.