Not everyone you know and meet is a good candidate for an online associate.

Consider carefully who you allow access to your social media profiles and personal information. This means people you allow to be a “friend” on Facebook or add to your friends list on Foursquare , for example. This can also extend to who’s in your network on LinkedIn or who you follow (or follows you) on Twitter. Social network “friends” and “followers” may potentially constitute relationships that could affect the outcome of background investigations and periodic reinvestigations associated with your security clearance. You may not need to consider your security clearance, but what about future employment?

Sort “friends” into groups and networks, and set access permissions accordingly. Add “untrusted” people to the group with the lowest permissions and accesses.

That's an Order! 10 Facebook Privacy Tips from the Marines