A good place to start is eating a person until they have welts, nailing parts of their bodies to boards, slapping them around until they cry or beg for mercy, depicting them in sexual act with animals, public and humiliating nudity and so on -- for the sexual gratification of others. Need I go on? How about doing anything in a sexual context to one of the "performers" that would make liberals scream "Torture!" if it was done to a prisoner in Gitmo as a good place to start?
Yeah, I know it's nice to imagine fuzzy and glamorous Playboy photos when people say "porn" but things have gotten a lot more coarse since the 1970s. And before you wax poetic about consenting adults, do you really think money and coercion never come into play?
and who gets the final call on that?
The People. That's why we have elections and stuff. If you don't trust The People to be sensible, then why bother giving them a vote?
Not really. We have a constitution and Bill of Rights to protect the rights of the people from the masses. These rights have been attacked many times by legislation and only judicial review has been able to protect them.