There is a local law on the books in my town. It is illegal to walk your dog on Sunday. I'm not making this up, it's a fact. This law goes back a good number of years, and is not enforced. However, I guess it's wrong to walk my dog on Sunday? Marijuana prohibition laws are based on biased, religious opinions, and not on medical fact. 72 million Americans admit to using it, making the laws ineffective, and showing that they do not want the law. So, it's wrong to smoke it because it's the law? Before 1929 when it was made illegal, it wasn't wrong?
Laws often have little to do with right and wrong.