SOCIAL media giant Facebook yesterday presented a long list of procedural objections to an Austrian court to try to halt a lawsuit alleging it violated the privacy of 25,000 of its users.

The collective, or class action, was brought by Max Schrems, 27, a law student who is claiming €500 (£362) in damages for each user. This is the latest of several legal challenges in Europe and the United States over the way Facebook shares users’ personal data with businesses or governments.

Schrems said it could become a test case for European data protection laws.

Lawyers for Facebook began the first day of hearings at a court in Vienna with a four-hour session in which they tried to convince the judge that the suit should not be allowed to proceed.

“The lawsuit is inadmissible on the procedural level – the court is not responsible,” said lawyer Nikolaus Pitkowitz. “It is unjustified in terms of content.”

Schrems accused Facebook of engaging in delaying tactics. He said: “This is a typical strategy, because most consumers will run out of time and money.”

The judge said a written decision on whether the court can handle the suit would be given before the summer.

Lawyers for Schrems and Facebook battled on technical grounds over whether the student had the status of a private Facebook consumer and if the 25,000 plaintiffs could legally allow him to pursue the action on their behalf.

Schrems has claimed damages for alleged data violations by Facebook, including by aiding the US National Security Agency in running its Prism programme, which mined users’ personal data. “I think we can heighten data protection with this lawsuit,” Schrems’s lawyer, Wolfram Proksch, said after the session.

The social media company’s lawyers did not address the details of the privacy concerns mentioned in his suit and declined to comment outside the court. If Schrems loses the case, a specialist financier will pay his legal costs – and will take 20 per cent of the damages if he wins – meaning users can join the case at no financial risk.

Schrems also has a case pending in Europe’s highest court, the European Court of Justice, which mainly relates to the so-called “Safe Harbour” agreement governing data transfers from Europe to the US. Those rules allow US companies to process data collected in the European Union once they “self-certify” that the processing meets EU standards of “adequate protection”, even outside European borders.

The European data protection supervisor told the court the agreement needed to be changed to safeguard the rights of European consumers and that corresponding requests for such changes had been made to the US.

British regulators have also investigated to see if Facebook, which has more than one billion users, has violated the UK's data protection laws.

In March, the European court heard a complaint that US technology firms and their Dublin-based subsidiaries were taking part in a global data "dragnet" in breach of European law.

The case was first raised at Ireland’s High Court, when the data protection commissioner was asked to investigate if Facebook was in breach of EU law for allegedly passing European users' data to US intelligence agencies.

The High Court had requested clarity on the Safe Harbour rules, whose effectiveness has been doubted by privacy campaigners and the European Commission since they were first drawn up at the turn of the century.

Critics said their worst fears were confirmed by former NSA contractor Edward Snowden's claims the agency's Prism programme required companies such as Google and Facebook to feed in users’ data.

Schrems asked the data protection commissioner to investigate how Facebook and its Irish subsidiary treated data originating in the EU, but was told it was a political matter and beyond the body’s remit. His lawyers argued that Facebook was subject to the Safe Harbour rules, which in turn are subject to the European Convention on Human Rights – and that the practices alleged by Snowden undermined these.

The commission found there was nothing to investigate because, in its view, Facebook was acting within the Safe Harbour provisions.