A new law being sought by the European Union would demand that websites permanently delete all data held about a user if that user requests that they do so. This would have a big impact on Facebook which is about as easy to quit as the Mafia. National law enforcement agencies would be given the right to go after companies thought to be violating such a law. The law would also mandate that users opt-in before their data is used in any way, which would also be a huge difference from current practices by companies like Facebook or Google. It's pretty easy to imagine, however, even in a case such as this that companies would make the idea of opting in very alluring.