Interesting question. I don’t (never have, actually) used twitter, yet it is used by tens if not hundreds of millions of users. that puts it in a category of services that resemble utilities, and therefore should be subject to some regulation.
Has anyone tried to come up with something similar? Is the concept somehow copyrighted or patented? These are questions that could lead to some sort of regulation.
When a service that almost everyone uses, has no real competition, and so, nowhere else for those that service purposely marginalizes/banishes, that infers a monopoly.