What are the good ideas under privacy on Social network project?

I am student and I have a final year project, I have chance to do it on the privacy on social network site (Social media) but right now I am in brainstorming phase. I couldn't come up with good idea that I can write a short proposal to my advisor. I need your help guys to advice me some of ideas about privacy issues rated to the end users. Keep this in mind I can do my work as technical side or based on user study.Waiting for your help thanks in advance