There isn't a point. It's simple enough- don't harm things except in self- defence. So it's perferctly OK to swat flies that (through no fault of their own) spread diseases. It's perfectly OK to kill an animal that's causing serious economic damage- but check that it's not simply being driven to desperation by human greed (or want). But to torment ANY animal for fun is not just inhuman, it's anti- life, you are justifying your own destruction on the DAYWBDY principle. And it's OK to eat animals - if you have leather and wool, you have a surplus of males that you've got to kill anyway (in the wild they are simply driven out of the herd as pickings for predators). Of course, some people take this to its logical conclusion- good luck to them, but I generally don't envy their health. So care sensibly, try not to be too greedy, and look on life for what it is- your own cousins.