>>4465957
There's really no way of preventing it. These are emotionally volatile girls, far superior to humans physically and extremely motivated to get what they want. Trainers are, informally of course, taught to consider it an honor and just let it happen to avoid any unpleasantness. Obviously the industry and its complicit journalists like Etsuko would never let a story like this endanger its family friendly image and lucrative sponsor deals.
Of course, this means the field tends to attract a rather specific kind of woman, which solves a lot of the problems just by itself.