If there is no God and there is no distinction between us and that of animals (excluding that of higher intellectual abilities),then it will be safe to have sexual relations with your mother,sister,father,daughter,cousin,your horse,your pet snake,your dog,anything and everything with a sexual organ. Laws against homosexuality,beastiality,perverts,rape,animal right will seem redundant and foolish as we are all animals and we have equal rights. You don't arrest a dog for killing a cat,or arrest a lion for killing and eating a deer. Everything will be a natural process as we are animals that don't need laws to curb our animalistic nature. Laws as we know it will be repealed, redressed and questioned critically. Laws against killing will be foolish and irrelevant because as animals,we need to ensure our survival,and if a stupid cop threatens that,i should kill him,burn him and eat him because i'm an animal and I can do no better. People will say that non-existence of God doesn't remove the empathy/moral code we all feel,but empathy is only felt when survival is not threatened and issue of morals doesn't exist for animals. If a man means no harm to me and i'm not hungry for his flesh,killing him will be against nature. We as animals don't kill for no reason. You could stay with a pack of well fed lions and they will do no harm to you if you don't threaten their existence. Animal rights will be removed as we are all animals,and such rights will be stupid to begin with in the first place. Human rights will be removed as we are all animals,and such rights will also be stupid to begin with. The universal law of nature will then be "do not kill for irrelevance( when not threatened or hungry) but do so with purpose"
Atheist don't think critically about their stand and the effect it can have on humanity as we know it. Most atheist factions separates themselves from atheist-perverts,atheist-cannibals and their likes because they can't understand the effect of atheism on humanity. Even if the US/World government is run by atheists,killers and perverts,these fools are wise enough not to ban religion and debunk it totally for the sake of humanity and the existence of law.