Facebook Twitter etc is what clowns would call, Open-source intelligence (OSINT) is data collected from publicly available sources to be used in an intelligence context. In the intelligence community, the term “open” refers to overt, publicly available sources where fools volunteer their private information...
Yes, all that and worse. It allows intel agencies to do very complex "node analysis" - in general your contact patterns as well as how frequently - but also allows facial recognition analysis (Google does that too BTW). Facebook also tracks your travel habits.
Now here's the worst part: prediction. FB data enables someone to predict how you will behave in certain situations.