Whenever you think of a court versus Facebook, imagine one of these mini mice trying to stick it to a polar bear. Or a goblin versus a dragon, or a fly versus an elephant. These companies are for the most part effectively outside of the law. The only time they feel pressure is when they can lose market share, and there's risk of their platform being blocked in a jurisdiction. That's it.
All they need to do is impose a three digit fine per affected user and Facebook will immediately feel intense pressure.
Might also be worth trying to force them to display a banner on every page of the site "you're on facebook, you have no privacy here", like those warnings on cigarette boxes. These might not work though, people would just see and ignore them, just like smokers ignore warnings about cigarettes.