[dragonwriter]

> Then to argue that virtual spaces are not protected by the first amendment contradicts the principles of free speech, and recent case law.

Since the citation upthread notes that even physical privately-owned common spaces are not protected by the first amendment against regulation by the owner of the space [0], though the first amendment rights of the owner also do not prevent state constitutions (California's in particular) from creating free speech obligations which do bind certain private owners of an extremely narrow class of public spaces, I think it is impossible to argue that virtual spaces are somehow protected under the first amendment by analogy to private common spaces, since the latter aren't actually protected.

[0] there is, IIRC, a different line of cases applying narrowly to government's or individual government official's use of privately owned physical spaces as a quasi-official two-way channel which does create some first amendment protection in that narrow context, and these principles have been extended to online fora, but that's not germane here.