It's more likely than not that the phone you carry has the Facebook app on it, and what Facebook and other tech firms do with the data we all share across their platforms is subject to a crucial ruling in the EU's top court Tuesday.
One young Austrian lawyer Max Schrems has been on a campaign to fix data sharing rules since 2013.
"The whole case is about NSA surveillance. If you share data with one of the big tech companies like Facebook or Google, they have to forward that information to the US security services in a way that is oftentimes described as mass surveillance."
If the name is familiar it is because Schrems already foiled a data-sharing deal between the EU and the US.
Judges at the European Court of Justice are deciding whether the Irish data protection regulators - where Facebook is headquartered - should be forced to stop European data from going abroad unless there are laws in place to protect it.
"The upside is that this is getting a lot of attention," explains Jennifer Baker - EU tech policy expert tells Euronews, "the downside potentially is that it could really disrupt data flows between the EU and the US."
While this case focuses on Facebook, any ruling could affect hundreds of thousands of companies and take a toll potentially on the global economy.
"After all what we want to achieve is that this new technology is actually serving the people and not just a couple of corporations or governments," Schrems remarks.
It's one of the most complex cases in Europe right now and will lay the groundwork for all future EU laws on data transfers.