I didn't see much Naruto nor Bleach cosplayers much o_o... Only at the Naruto photoshoot and Bleach photoshoot really (of course)...But other than that: I didn't see like it was SWARMING of them. >_>
Besides, you can't stop them from cosplaying from those animes. It's really popular so, of course, you're going to see some around the con. In ANY anime/comic convention!
I actually saw more Deathnote around than Naruto or Bleach. O_O Other than the gathering time and places, that is.
You can't stop people from cosplaying as a character they like. Especially from such well-