Facebook is an exJW minefield.
Things can get through to people you don't want them to get through to. However, make sure you go to your privacy settings and choose who can see what. There are things you can do to TRY to keep things from getting seen by the wrong people. But if you are on facebook and living a normal life, that picture of you at someone's birthday party may be seen by some witness somewhere. It's a small world. The 7 degrees of Kevin Bacon and all that. After a few incriminating instances and lots of people unfriending me, I decided to not freak out (tho I'm still cautious.) Like the old adage, the people who matter accept you the way you are. The people who don't dont matter. But as an ex witness it's not always as simple as that. Be careful on FB.