From craigslist...see photo and "reply-to" info posted here:
My roommate and his gf found this 6 mo- 1 year old cat Tuesday night near Greenwood Ave and 125th. He's orange with white paws, super sweet and friendly. He's clean, but didn't have a collar or a chip. He isn't fixed. We think he must have an owner who's missing him. Let me know if he's yours. Thanks "
Reply to craigslist email: firstname.lastname@example.org
(This is the only contact info given so far.)