I'm saying that the argument that we're observing capitalism at work is false.

> Is monopoly in general a failure? Or is it AT&T in this particular instance?

Monopoly is in general a market failure (which is why antitrust laws exist). Therefore AT&T having the position it does (not a monopoly, but an oligopoly at best) is a market failure.

> Is regulation the opposite of what capitalist economies should have?

My understanding is that capitalism (in the sense that the great-grandparent post was using it) is something that involves not having regulation. Since AT&T's position is a consequence of this regulation, the assertion that we're observing capitalism (in the sense I think the great-grandparent used the term) is false.

I dont know why you have been downvoted. You have a valid question. If monopoly or oligopoly is the situation all markets gravitate towards if left unchecked by regulation, then these situation are not failures but expected outcomes of capitalism. Why are these outcomes not considered effects of the invisible hand?