If you don't see a link to send them a message you can ask them to be your friend or you can hunt for one of their friends who does allow messages and try and contact your person through them.
Sensible facebook private profile viewer Plans
I suggest checking your privacy settings every time you log in, if not at least once a week.
Merely because it is worldwide, you'll see nations taking part in it like Spain, the uk, Portugal, Eire, Luxembourg, France and even Austria.