no longer have to marry to live together legally in NC...who knew?

So an NC Court just struck down a law requiring couples to be married in order to live together. I have to say I am more than a little surprised that this law has been on the books as long as it has. Surely there are probably very few times that it has been enforced but I think that I am more confused by how marriage and cohabitation is refered to in OTHER laws. For example - common law marriage? You would have to break the law to be common-law married? doesn't make sense. Whatevs!