There's a distinction to be made here - breaking laws because you're unaware of them is not the same as breaking laws just because you don't agree with them. Also some people choose to break laws that they agree with just because it seems convenient (or there's no deterrent) at the time - speeding being the obvious example.
Tricky question... Martin Luther King jr broke some laws (Letter from Birmingham Jail?), and he's considered a hero... It depends how strongly I disagree with the law, but more-so how unethical I believe it is...