@Jim -- the difference being that if it's government controlling them, there is no other choice, and the govt would (presumably) defend their monopoly. If it's one or more private companies running it, then the customers have no obligation to use their services. If the company fails to stop satisfying the marketplace, that opens the door for another company to come in and take their market share. That's why, absent of government force, a true monopoly is really not possible in a free market, unless the company is fully satisfying all their customers.