The first murder was committed with a rock. Shall we ban all rocks? After all, there are a lot more rocks in the world than guns. Let's deal with the real problem: evil in the hearts of men.
Not a revenge-oriented person, but really. No need to even avenge ourselves. (1) God is our avenger (2) Bitterness is poison (3) Some people just don’t deserve that place in your life. Hate and bitterness take too much energy that could be put.