It is disappointing to read once again how a high-ranking official's complete lack of understanding of how the Internet works got her in serious trouble.
1. Never use any computer that is not your property for posting personal items, i.e., jokes, anecdotes, photos, and other things you would not want the entire company to know came from you.
2. Facebook has NO privacy. Never post pictures of yourself that you do not want to share with the world. Do not post incendiary remarks on Facebook, especially in "Private Groups."
3. Finally, imagine your worst enemy knowing everything about you. With only a few ill-conceived posts you can accomplish this.
4. If you insist on hell-raising, create a persona in Disqus or others like it, and make sure the pseudonym has nothing to do with you. For example, never allow it near Facebook! Investigate TOR as a possible solution.