Is it illegal to try to obtain someones last name to get pictures online of them?

you did not break any laws, but why not just ask him straight out if he even has a Facebook account ? not everyone has one. And then ask him again to his face if you can take pictures of him--why so shy about doing that ? Also, what if he is married, or has a steady girlfriend ? You COULD be messing that up for him if he has no interest in getting a new girlfriend at this time.