I know they know better

It amazes me what people will do even though they know better. Even if it hurts someone, they do it anyways. Unfortunately some people never get bit on the butt by karma. So since they pay no consequences they repeatedly do it. Why is it that some people are affected by karma and some are not? If you wouldn't want someone to do it to you or someone you love, you shouldn't do it. If affects anyone else in a negative way, you shouldn't do it. Don't accept bad behavior because if you ignore it then it will become a common occurrence. What happened to common decency, common courtesy and common sense?