A privacy campaigner faces going bust over a landmark battle to find out what Facebook tells US spy chiefs unless he gets commitments on legal costs.
Austrian law student Max Schrems, who sought an audit on the back of whistleblower Edwards Snowden's expose of the Prism surveillance op, warned the lawsuit could leave him bankrupt.
The High Court in Dublin has deferred sending the case to Europe's top court after the activist said he first wanted assurances on potential costs.
"I'm taking on the possible liability of a couple of hundred thousand euro in this case. There's no need to go bankrupt over it," Mr Schrems said.
The campaigner's initial attempt to have the social media giant audited in Ireland, where its European HQ is based, was dismissed last year by Ireland's Data Protection Commission.
Mr Schrems wants Facebook scrutinised by the watchdog and to release the information it has sent to America's National Security Agency (NSA).
But now he has revealed he will not proceed with his challenge without assurances from Irish authorities that they will not pursue him for their court fees.
Mr Schrems has filed another 22 complaints about Facebook with the Data Protection Commission.
Judge Gerard Hogan last month ruled that the European Court of Justice should rule on the law on data sharing with the US known as the Safe Harbour agreement or if the watchdog can audit Facebook.
Concerns were raised about Mr Schrems' costs at a hearing in Dublin.
The judge said: "There's no doubt that very serious and weighty issues have been raised in this case.
"I would think it unlikely, but that would maybe be presumptious on my part, but I think it unlikely that the court would make any adverse order in this situation."
Mr Schrems' barrister Paul O'Shea added: "My client has addressed this... and said that he does not want to be one of the unlikely ones."
Mr Schrems, who campaigns as part of the Europe-V-Facebook pressure group and who was in court, has raised 50,000 euro in crowd-funding to help fight his case and others.
"Officially the Data Protection Commissioner is the regulator but as far as we are concerned they are just not doing their job," Mr Schrems said.
The current commissioner Billy Hawkes is retiring and a replacement is expected to be in place in August.
Lawyers for Mr Schrems sought assurances in the High Court that no adverse order would be for costs against him or that ultimately any order for costs would not exceed a reasonable amount.
They are awaiting a response from the Data Protection Commission ahead of Judge Hogan detailing the reference to be made to the European Court of Justice.
It is hoped the case can be formally referred to the Luxembourg court on July 16.