Comment by nradov

Those are not big secrets. You can find history textbooks which explain how to become a dictator and order your minions to commit genocide. You can find plenty of recipes online which explain how to manufacture chemical weapons. In particular the original chemical weapon chlorine gas is rather trivial to create.

And yet genocide and use of chemical weapons are still fairly rare. Most people choose not to do those things, and there are a number of practical obstacles. Knowledge or lack thereof isn't the issue.