"The individual"
If the individual wants to form a gang or a militia in order to take control(or "not take control") then individuals will do it.
They are obviously inclined to do so(as evidenced by the presence of government).

Your confusion is in believing that an entity can prevent itself.
Government stopping a group of people(with a militia) from taking over is as silly as believing that rabbits will stop long eared rodents from eating the vegetable garden.

If you put rabbits in your garden to stop rabbits then you are...well....
You are in the exact same boat as people that vote in order to prevent a group of people from taking over control and forcing their will on others.