Students can share information in a variety of ways.
Teachers must be careful when using social media.
Like all social media, once it is out there it cannot be deleted. Teachers must be smart and professional about the things they post. If you are worried about who sees the post then it shouldn't be done.
Don't be scared of social media because concerns, share the excitement of your classroom with others.
Be vigilant about the things others post on the page. If others can post then the teacher is responsible for things on that page.
Spend time so students fully understand expectations and consequences of inappropriate behavior.