Why should you obey the law?

Justice Louis Brandeis said:

"In a government of laws, existence of the government will be imperiled if it fails to observe the laws scrupulously. Our government is the potent, the omnipresent teacher. For good or for ill, it teaches the whole people by its example. Crime is contagious. If the government becomes a lawbreaker; it breeds contempt for law; it invites every man to become a law unto himself; it invites anarchy."

Powerful words.