The idea is that any user supplied data has to be separated into two groups: Privacy relevant information, which has to be stored encrypted, and can not be used for advertising, for training models, etc – like communications, private messages, email, etc.<p>And into user-supplied not-privacy-relevant data. The results of users filling out captchas, classifying info for training of neural networks, the data from Google’s MapMaker, etc.<p>In the case where these two sets of data overlap, privacy is more important, but on request, the company has to hand out every data you ever gave them in a machine-readable format. So if you decide to leave facebook, they have to give you a .zip with your photos, your posts as xml, etc.