i honestly remember reading on here about a cab driver asking questions on how to get past the lock screen that was password protected. He said he found a phone in his cab. Could be your guy. I tried looking for the post. Couldnt really remember when the topic was called. It has been in the past 2-3 weeks. Hope this helps...
^ This was posted on Monday, the OP said it happened Saturday night. Assuming we're talking about recent Saturdays, that would exclude 2-3 weeks ago. My guess is if a cab driver found a phone 2-3 ago then it is not the OP's.