I don't know for sure if laws act as a deterrent, but I would guess they do, because people would fear being caught and going to prison. I do think that, either way, locking of people with criminal type minds helps protect society from said people. But that doesn't mean I necessarily believe laws and punishment should exist. I don't really know. I can't answer the second question because there are way too many possible activities to categories as should/shouldn't be a crime. I will say, because it seems pertinent nowadays, that I believe in freedom of speech.