Citing the law as a justification of the law is a cyclical debate that is logically flawed.
It's called "civil disobedience". Clearly these people are at odds with the law and do not agree with it. When people feel that a law is immoral or unjust it will sometimes morally behoove them to publicly violate it as a form of demonstration. The entire civil rights movement was based upon this philosophy. Even then people were saying things like, "That's what those idiots get, they knew damn well that it was against the law for coloreds to go into that deli and drink from the white people fountain."
Clearly they are breaking the law, but the debate here is about whether or not the law is valid.
"Ordinarily, a person leaving a courtroom with a conviction behind him would wear a somber face. But I left with a smile. I knew that I was a convicted criminal, but I was proud of my crime." ~Martin Luther King, Jr., March 22, 1956