Ah, so we shift from the legal to the philosophical.
When folks say they care about what's right rather than what's legal, I applaud them. But lots of times, what they mean is, I can ignore laws I disagree with. I can violate copyrights laws, I can smoke a little dope, I can drive as fast as I want.
There are many circumstances in which good and law are incompatable, and we should all choose the former. But most of the time when people ignore the law, it is because the greater good protected by the law conflicts with their personal self-interest.
So why worry about what's legal?
One, whether you are morally right or wrong, if you break the law, there can be consequences.
Two, America (and probably many nations represented on this board) is a democractic republic --- if you don't like a law, you work to change it, or you go to a different state.
Three, I went to law school to do good. I wish that my life were as simple as D&D --- kill or be killed. Good guys and bad guys. The legal profession, as my peers on the board will agree, is seldom so clear-cut. But like any paladin will tell you, law working in the service of good is powerful stuff.