Some 25,000 Facebook users are suing the social network over claims of privacy breaches. The class action suit will be heard by a court in Austria today.

It has been brought against Facebook European headquarters in Dublin, which registers all accounts outside the US and Canada.

This makes up about 80% of its 1.35 billion users.

The action is being led by Austrian data protection campaigner Max Schrems (27), who wants to stop what he calls 'mass surveillance' by the social networking site.

The lawsuit claims Facebook has infringed on rights in the way it collects data about users, and monitors their use of 'like' buttons.

"Basically we are asking Facebook to stop mass surveillance, to (have) a proper privacy policy that people can understand, but also to stop collecting data of people that are not even Facebook users," Mr Schrems told AFP in an interview.

"There is a wide number of issues in the lawsuit and we hope to kind of win all of them and to get a landmark case against US data-gathering companies."