Try as they might, they can’t get out. The chains around their respective wings and horns cause instantaneous tazing to the entire group the second it detects any activity, and the same goes for the extra chains on the earth mares’ legs, and the chains around Pinkie’s mane and tail. Because you do not trust that pony’s hair worth a lick. Other than that though, they’re free to struggle and thrash about as much as they can, all for your entertainment.