extreme photo's

i want to know why we cant post nudity or sexually explicit pictures. there should be an application where this is allowed and restricted access is permitted. requested access only and no option to copy pictures. it sucks to have to be a member of two sites for the same purpose. with the exception of sharing nude pics. rating pics should also be an option. maby have three levels of nudity..regular ( meaning naked bodys) medium ( meaning two people and the possibility of toys) hardcore ( most likely stuff people downloaded form the internet..EXTREME) voting for pics would also be a great idea. thanks