oh also perry's title was "you do not own your own genetalia". of course you do. it's that property rights are not absolute (if they were, for example, there couldn't even be a discussion about downloading music, the case would be closed already. "you can put music you own up for download because you own it" would be the end. it's absurd to try to solve complex moral issues this way.). but Perry apparently can't even imagine the idea of non-absolute property rights, so concludes an absurdity instead.
Deriving objective notions of morality are not easy, but a critical preference for this or those moral theories are the basis for any rational analysis of social interactions. Your simplistic assumptions of how I derive my theories, for example, seem based on the idea I cannot imagine non-absolute property rights. Yet, as the 'Karl Popper' book at the top of Samizdata.net blog might have hinted to you, the only think I cannot imagine is absolute certainly about anything. My opposition to outlawing genital piercing is based on a critical preference for a moral theory called 'self-ownership'.