What? Did you just say that? Yes, probably they do use Facebook for personal connections, but what about using it in the classroom?
Facebook is blocked in my school but there are tons of ways you can use it without having access on campus. Here are some ways:
1. Setup a class (closed group).
2. Hold discussions, project/homework questions/answers.
3. Invite a "guest speaker" on the page.
4. Post outside, online resources for projects or research.
5. Post polls, publicly shared on their individual pages to get more responses.
There are tons of ways to incorporate FB into your classroom. Check out some of these articles for more ideas:
Ways to use Facebook effectively in class
100 Ways You Should Be Using Facebook
10 Ways to use Facebook as a teaching tool