[satyrnein]

If you're deemed a common carrier, you can no longer exercise full editorial control over the content you're carrying. We've gone back and forth on whether ISPs are common carriers or not. Twitter is a step even further, but possible.

[qsort]

Sure, but does the comparison really hold? ISPs provide a service that's strictly tied to very expensive and hard to duplicate infrastructure (often with strategic significance, even). To make an even more extreme example, if the companies controlling the North Atlantic TAT cables suddenly decided to arbitrarily deny service we'd have a huge problem, nobody is denying that. But social media are literally a database and some javascript, that's not even remotely in the same league.

Again, I do agree we have a quasi-monopoly problem; but if we do, the logical solution is to break the monopoly. Imposing political control creates more problems than it solves.

[satyrnein]

Agreed that social networks are not natural monopolies due to physical characteristics, but the network effects are still significant barriers to entry. Another angle is mandating interoperability of some kind, such as mandating that mobile carriers had to support porting of phone numbers. None of these ideas seem like a slam dunk, though.