Be smart about what you put online. Come on, guys.
Tips and tricks
Remember that nothing online is temporary. Keep your profile private. Keep your passwords private, and change them often. Don't post stuff you wouldn't want your parents seeing, and don't reply to stuff of that nature sent to you. Be respectful. Be aware of copyright laws. And google yourself every once in a while.
Don't be an idiot online.
Be smart about this stuff.