I hate to answer a question with a question, but why do you care how other people choose to dress? Do you really think people should be jailed for freely expressing themselves? Who are they hurting by choosing to live their life how they choose? Do you have children that you wish wouldn't be exposed to what you consider indecent?
In some cultures women don't wear tops, and men in my country would consider this indecent, but it's normal in another culture. In some cultures, women are mutilated by men to take away their pleasure, and that is ok by their standards, and horrible to ours.
We are all born with a bare ass. Who am I, or you, to judge others.