An Austrian court has approved a class action of some 25,000 people around the world against Facebook. The social network is accused of breaching its users’ privacy. A preliminary hearing into the complaint has been set for April.

"The hearing on April 9 will consider the admissibility of the lawsuit," Beatrix Engelmann of the Vienna regional court for criminal matters, told AFP.

The lawsuit was first filed last August by Max Schrems, an Austrian lawyer and founder of the group Europe versus Facebook. Schrems had already challenged the Irish Office of the Data Protection Commissioner (ODPC) in 2013 by demanding an inquiry into the activities of US companies, including Facebook, to assess their involvement in the NSA spy scandal. The action resulted in a privacy audit by the data protection commissioner.

READ MORE: Facebook given deadline in ‘largest privacy class action in Europe’

The group has described the new lawsuit, joined by 25,000 users from Europe, Asia, Latin America and Australia, as “the largest privacy class action in Europe.”

However, US and Canadian users won’t be able to participate, as the lawsuit is filed against Facebook Ireland, which runs all of the company’s operations outside North America. The group stopped accepting sign-ups after the first 25,000, but more than 50,000 additional Facebook users registered on the group’s website to express their will to join the action should it expand.

Schrems claims that Facebook’s practices are in violation of European data protection law, that it supports the NSA’s PRISM surveillance program, involving the unauthorized passing on of user data to external applications and the tracking of Internet users on external websites. The existence of PRISM program was leaked to the public by whistleblower Edward Snowden in 2013. PRISM is a mass electronic surveillance data mining program launched in 2007 by the National Security Agency (NSA). The plaintiffs are demanding €500 in compensation for each supporter of the class action if their allegations are supported in court.

However, the compensation is not their ultimate goal, which is rather to force Facebook to change its policies to ensure users’ personal data is protected. They also demand a “suspension of data usage” by the social network.

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The group’s webpage says that Facebook has denied the claims.

“Facebook so far remains silent on the alleged violation of European privacy laws and instead focuses on formalistic counter-claims,” the group’s press release said. “Facebook simply “refutes” all claims across the board, without explaining why. Facebook simply claims that it cannot be sued by its users.”

The group’s lawyer, Wolfram Proksch, said Facebook’s objections lacked any substance and called Facebook’s arguments “bizarre,” TechCrunch reports.

Facebook’s privacy policy is under investigation in several European countries as the company announced new changes taking effect January 1, which may violate data protection laws. Later Facebook delayed the regulations entering into force until January 30.