Key words "supposed to be" but in reality there's at least as much regulation creation at the behest of corporate lobby as a barrier to entry against competitors. And notice how the median reliability and performance of the big three is worse than in countries where internet access is treated more like a public utility.

But that's basically what they are, they're natural monopolies but are in some ways more heavily regulated as if they were competitive businesses where anti-competition law would be easier to execute. Notice wherever Google Fiber tries to move in how much better service and performance gets while at the same time the local one or two choices step over themselves in outrage.

If the music industry were saying "punish them! turn off their water!" people would probably better understand just exactly how vindictive they're trying to be.