If the CJEU allows a pan-European class action to proceed, it could have significant consequences for Facebook and other online companies operating in Europe, Ars Technica reported.

Facebook has argued that class action is inadmissible for procedural reasons, and that the Austrian courts have no jurisdiction in this case, the company’s European headquarters being in Ireland. The lower courts in Austria had a different view, and now the country’s supreme court is asking the CJEU to provide a definitive ruling on the issues.

The legal disputes between Facebook and Mr Schrems have already brought down the data transfer deal Safe Harbour, which has since been replaced by another agreement, Privacy Shield.

Fortune has published an extensive piece on the background and potential ramifications of the class-action case.