Silly politicians. Why don't they just pass a law to make it illegal for drug cartel members to own guns? Wait, wait, wait, I have it. Why don't they require drug cartel members to register as drug cartel members?
Geez, if I can solve the problem so easily, why is it so hard for the government to do it?
You're not thinking big enough. Why not just pass a law banning Mexican drug cartels?