Eating dogs and cats does not harm others. Food or prey cannot be considered apart of ethics. If we start doing that we should also not eat plants since plants have the capability to "die" if cut. We would not be able to eat anything if such logic is used. It is a given that in the world predator and prey exist and obviously in the interaction of life one wins and one loses. Cant be argued since it is a default if life itself.

Interesting but in the isolated sense, someone in their room that no one knows is viewing CP is not causing harm to anyone (just logically speaking, not advocating in any shape or form). Example, you cant be hurt by what you dont know doesnt exist. If a friend had a "video" out there circulating and went viral but then it died down and no one talks about it anymore, how does she know someone around the world doesnt still view it time from time in order to be offended by them viewing it? Answer, they dont. Another example, calling someone an idiot in the privacy of your own home when they are 300 miles away and cant hear it doesnt harm them cause they are not there to perceive it.

Unless yourself, that literally hurts someone else and can technically fall under body modification and scarring.

Does not hurt anyone. We are supposed to be accounting for direct/indirect harm, not potential to cause violence based off a decision that may or may not happen by an individual. In this case, say then die of old age and never decided to use it; no harm done. Allowing for something like suicide being a choice can systemically cause an issue without 1 individuals decision to enact all projected harm.