I am not a huge fan of Fb or other soc media, but I consider this data mining era as unavoidable and from other hand, some day all that info might even help humanity (or damage it, of course). So, we can consider this power as a Pandora's box and I am pretty happy that it is only there in FB (well, and Google, Microsoft, etc.) and i am pretty sure you, as well as many others would like to open that box and see inside. Good is that you, or me, or anyone else cant do that. Good is that if something will go very wrong, we will know who to blame. But nothing will go wrong as long as bad guys (who afraid surveillance) does not have a chance to touch that box.
Eh? No comprendo! Nothing is unavoidable. If you really are from Lithuania you should go and ask some older people what they think about personal data collection. Having lived under USSR I'm very sure that they don't like that, as they have seen it can suddenly be used against them.