> Near the Washington Post article's end: "Throughout the trial, AT&T lawyers had argued that this "dismemberment" would hurt the nation's telephone network by raising prices to consumers and resulting in a deterioration of the phone system the nation depends on for defense communications and other emergency situations..."

Excuse or not, this technically is true and it is possible things like this happen.

...but! Entry cost for telephony then (=building a whole new, alternative telephone network) is so expensive, that it's unrealistic to build one, except maybe in places with such population density, that the cost of new wiring is offset by the number of new customers in a small area.

Compared to pulling new telephone cables for the whole country, making a new social network is very fast and cheap (apparently, takes 13(?) employees in case of instagram), and allows a slow-start (run the network on one $5 virtual machine, then get another, and another, then have issues with scaling and technical debt, but slowly fix stuff when money pours in), which means that even if facebook fails horribly after the breakup, 'someone new' will fill the gap.

In AT&T's case, the second link ends with the DoJ saying the FCC should've regulated better.

For Facebook, I think we wouldn't want just another giant Facebook2 to pop-up in it's place. It's important that the FTC (or Congress) stress real data portability, privacy regulations and even protocols/standards if needed to tie everything together in a post-Facebook social media. Though I have doubts about just how much of this will be accomplished.