Facebook is being sued by two users in the US for allegedly intercepting information mined from private messages and selling that to advertisers without users' consent.
Mathew Campbell and Michael Hurley have filed the class action lawsuit against Facebook with the Northern District Court of California, claiming that the social media giant has been scanning private messages that contain URL hyperlinks "for purposes including but not limited to data mining and user profiling", which is a violation of the Electronic Communications Privacy Act.
In a statement Facebook said: "We believe the allegations are without merit and we will defend ourselves vigorously."
The lawsuit cites research from Swiss security solutions firm High-Tech Bridge, which conducted a test of the 50 largest social networks, web services and popular free email systems in the world to see if these services were monitoring links.
Content of emails
Six of the 50 services were found to monitor and access hyperlinks sent in messages, namely Facebook, Twitter, Google+ and Formspring, as well as two link-shortening services.
Google's free email system Gmail was sued in 2012 for creating text ads based on the content of emails, while Google argued that users had consented to having their emails read for the purpose of targeted advertising, by the very virtue of signing up to become Gmail users.
Also included in the lawsuit's documentation are news reports about Facebook third party plug-ins being used to count "Likes" shared through private messages, including articles from the Wall Street Journal pertaining to its 2012 research into digital privacy
"Representing to users that the content of Facebook messages is 'private' creates an especially profitable opportunity for Facebook, because users who believe they are communicating on a service free from surveillance are likely to reveal facts about themselves that they would not reveal had they known the content was being monitored," claim the plaintiffs.
The lawsuit also points out that while Facebook has been publicly complaining in the media about pressures put on it by the NSA to monitor users' activities, and how it refuses to give governments access to users' data without a warrant, the social network shows no qualms about selling the information to companies, that could retain the information indefinitely and use it for "any purpose".
Facebook has modified its privacy settings numerous times over the past few years, and has often been criticised by users for making the settings difficult to understand and access, as well as changing settings so that users' profile content suddenly becomes public, often without the user's knowledge.
In October 2013, the social media giant announced that it was taking away the ability for users to hide themselves from search results, sparking a backlash from many users.