Schrems, who lives in Austria, accused the social media firm of breaking several data protection rules, and had asked an Austrian court to allow his case and those of seven others--users in Austria, Germany and India--to be combined into a collective action.

Facebook, which runs its EU services in Ireland, had argued that Austrian courts did not have jurisdiction over its Irish operations, and that Schrems was a “professional” user and therefore not covered by consumer protection provisions.

On Thursday, the European Court of Justice said that a Facebook user could be considered a “consumer” if their use was “predominately” for personal and not professional use.

Consumers can file complaints against activities in another EU member state in their country of domicile, the Kirchberg-based judges said.

However, under the same set of European rules, consumers in other countries (in this case, Germany and India) cannot selectively choose to file consumer cases in an EU member state where they don’t live (such as Austria).

“The same also applies in regard to a consumer to whom the claims of other consumers have been assigned,” according to a court statement, referring to class action lawsuits.

The matter now returns to Austria’s Supreme Court for adjudication.

In an emailed press statement, Schrems said:

“For three years Facebook has been fighting nail and toe against the court’s jurisdiction in Austria and lost. Now, we can finally go ahead with the case. Facebook will now have to explain to a neutral court whether its business model is in line with stringent European privacy laws. This is a huge blow for them. Unfortunately, the Court of Justice has not taken up the golden opportunity to finally establish collective redress options in Europe, but kicked the ball back to the legislator.”

A Facebook spokesperson told Delano on 25 January:

“Today’s decision by the European Court of Justice supports the previous decisions of two courts that Mr. Schrems’s claims cannot proceed in Austrian courts as “class action” on behalf of other consumers. We were pleased to have been able to present our case to the European Court of Justice and now look forward to resolving this matter.”

The case is C-498/16 (Maximilian Schrems v Facebook Ireland Limited).