If you can end one problem in the world, what would it be?

One problem I see in the world is that bad influences are influencing other people to do the same thing they are doing. This is the one problem I would like to solve because this can affect everyone. Anyone can be influenced to do something that they are not supposed and then it turns into a habit. And if it continues, they would influence other and so on. A solution to this is by banning things like weed, guns, cigarettes and etc. By doing this, most people will not be doing all of this and they will not influence their friends. This is important for people to know because they would realize how bad it is and more people would take a stand to ban and to jail everyone who is influencing this. This is important to me because it would be sad to my family members and friends be influenced by this things/people. All I can do to stop it is by trying to be positive to those around who are going through this and by telling them to not doing anything bad. This is the one problem I would try to solve.