How Facebook suggest a big % of known people with a brand new account?

I've just created a new Facebook and I see a lot of people I knew. I didn't input any relevant data, only a fake name and email. How is possible? Maybe it's tracking me by ip? I have another account with those friends, but is in another browser user (chrome). Even real people show up that are not friends with me in facebook..<p>What it's happening?