Most people don't check their social-media terms and conditions; and that's understandable: it's long and boring and is often deliberately written that way to put people off; it's lip-service to the ideas of 'privacy' or 'asking permission'. It's the cynical layer of legalese that sits below the bright, smiling logos and the cheery façade of chummy StartupSpeak. The act of you thumbing that Gorilla Glass button gives them the rights to do what the fuck they like with all sorts of information you probably didn't even know they had.
But you should read as much of it as you can bear. Understand it and then negate it. You can switch off whole layers of this stuff, but you gotta make the effort. It only takes minutes. In fact, go in now and switch off everything about yourself you can - your location, birthday, gender, age - anything that makes you more of a commodity. Sure, they've got scripts that can second-guess that info from your tweets, but don't offer yourself up so easily. Put it another way: you're paying a phone-bill for them to freely advertise third-party services and sell off bits of you to vested interests. You are not only the commodity, you are also the self-paid infrastructure that allows your own sale. Switch off as much of it as you can.