Do you ever turn down friend requests on facebook?

I generally feel like asking people to be friends is intrusive. So far, I’ve only asked friends from college or my family members. My daughter, who started at the same time as I did, already has 89 friends. My sister has hundreds (I don’t know when she started).

So I was thinking about it, and wondering if I would turn down a friend request, and although I’m a misanthrope, I thought the only circumstance would be if I didn’t know the person. Even people I despise, I might accept, because it’s weird not to (I think). Not every site is like fluther where you can follow a person if you want, but it’s all voluntary (although some people feel if they are fluthered, they must fluther in return).

So, do you turn down requests? If so, under what circumstances, or why do you? If not, why not?