Do you think kids/teenagers should learn Marshall arts or karate?

I'm highly looking into getting my kids involved in something like this for defense of themselves when they're older. So many things going on so much bullying in schools that innocent kids are involved for no reason and are victims. Sometimes even death is involved. I know this type of activity won't make situations any better but I will feel more secure as a mom that my child will learn to defen themselves in any situation wether as a kid or adult.