That's a good observation, but doesn't really get at the point the parent was making. If I may continue the example of First Amendment rights, consider the well-founded prohibition on yelling 'fire' in a crowded theater, which seems more or less in line with an ad for boots on the Internet.

Could you address the issue of only allowing a user to post one comment at a time? I think the parent made a good point on the potential chilling effect that may have on parallel comment threads.