How well do you have to know someone to add them on facebook?

[John Doe]

If you become actual friends with that person? If the person is friends with your friends, but youve only really said hey to them (if that)? Or if you just notice they have some mutual friends and have never met them in person at all? I see girls who just add random people they dont know, but can/do guys do that too?

[Herp Derp]

You don't have to know them at all! I friend people I don;t know all the time, and we become friends.

[anonymous]

I have facebook friends that i've never said a word to, over the internet or face to face! You don't really have to know them at all, but adding them is a great way to get to know them!

[Lois]

I don't add anyone, but If I get a friend request and I've seen them around school/ met them briefly or the mutual friends are a massive amount I'll tend to except. And it's fine for guys to do that!