Facebook is using you, whether you know it or not. Sometimes it's obvious: you like a page, you click share, Facebook benefits. Other times, you have no clue until a friend asks you about a photo they saw that you liked. The unfortunate side-effect to all of this is that it can actually make you an unbearable annoyance to your friends, and you probably don't even know it. Here's how it works, and how to stop it.