It's a way of deliberately breaking the spirits of animals so humans can use them. Crushing involves tying up and literally beating an elephant into submission.

"Tourists may think activities like riding an elephant do no harm," Dr. Jan Schmidt-Burbach, senior wildlife and veterinary adviser at World Animal Protection, told The Dodo in a May 2015 feature on this kind of cruel tourism. "But the brutal truth is that breaking these animals' spirits to the point that they allow humans to interact with them involves cruelty at every turn."

While it's unclear exactly how many elephants endure this torment each year, it's believed that one of the main threats to elephant populations in Asian habitats is the illegal capture and "training" of young elephants.