Facebook case may force European companies to review their widespread practice of storing digital data with American tech giants, following the court accusation of the US intelligence services of conducting mass surveillance. The European Court of Justice delivered its influential opinion, which is a significant development in the battle over online privacy, even though it is yet to be confirmed by the Luxembourg court.

The recent ruling was the latest victory for the Austrian campaigner Maximilian Schrems. The latter initially brought a claim against the social network in Ireland after Edward Snowden’s revelations about the NSA activities.

So, according to the recent court ruling, if any European country believes that transferring information to servers abroad may undermine the protection of citizens, it can suspend such transfer.

According to the Luxembourg court, the Safe Harbor agreement between the United States and Europe, which provides spies access to huge banks of information, does not stop watchdogs from investigating complaints or suspending the transfers. The Safe Harbor arrangement allows the National Security Agency to use the Prism surveillance system and wade through personal data held by 9 tech giants.

Now the ruling could have major implications for data flows between Europe and America, as well as for US Internet companies operating in Europe. Schrems pointed out that while his case was specific to Facebook, the court ruling may also apply to other companies, including Microsoft, Apple, Google and Yahoo. In the meantime, the final ruling by the European Court of Justice is expected later in 2015.