there has to be a standard for society, as a whole. if everybody thought like you and considered themselves under their own, personal law, rather than as a part of a collective community it would be chaos.
when you're living on a remote island, completely alone, you can make your own 'rights,' but until then, the government [read: 'of the people, by the people, for the people'] has set your 'rights' and the laws we all have to live by.
we have a lot of freedom here, but that freedom is with the understanding that we'll act like responsible citizens and do the right thing.
those who choose to ignore what they have and do whatever they want, regardless of the law, deserve to be locked away.