Friend requests from people I've never heard of?

[Hallo.:)]

I don't know how they find my profile because I have my Facebook security settings on very high. I have no friends in common with them, and I've found that they are mostly from men of middle eastern descent. When I message to ask them who they are, they say, "Hi, I _______, wish we be friends?". How do they find my profile? And has my information been given away or something?

[Vlar]

Someone is giving them your name and/or link. Perhaps you've signed in to another site with your FB login?