Cosplayers have it rough. It's not simply coming up with the outfits and posing for all those pics. It's also the jerkwads they have to deal with.
Of course, not all cosplay photographers are bad people—many are very good people. But according to Japan's Weekly Jitsuwa, there was apparently a "tousatsu team" (盗撮チーム) or "Peeping Tom team" making the rounds at the recent Tokyo International Anime Fair. This team was apparently snapping illicit cosplayer pics.