Well, I thought that was a shop and that arch had pulled off a beautiful super-win troll, but I checked the EXIF data, and... well, from what I can tell, the photo's legit. iPhone 4S, taken at 2012:08:23 21:08:58, 4.3 mm focal length, etc.
Anyway, if the photo is in fact not shooped, then yeah, he obviously goes on the site at least periodically because that image is only available on this site. Just walk up to him and be like "what's your username".
I mean, that's of course if he can make room to talk to you; his schedule's probably full of the insane amounts of -blam!- he's netting with that sticker.