Well, free speach here is not a right or entitlement, it's a privilege, which can be revoked. IMHO, defamation is a valid reason for revocation.
Ok, a little bit of Devil's Advocate here:
Everyone's harping on the technical/legal definition of "free speech." i.e. The First Amendment to the United States Constitution which allows for freedom of religion, of speech, assembly, the press, and all that other good stuff. And yes, that's not applicable here because this is a private forum where the rules are not set by any governmental organization but by the people who own/operate said forum.
Right. Asked and answered.
But, and I think it's disingenuous to try and deny that this sort of thing exists, there is always a "hive-mind" mentality on any public forum - an established circle-jerk narrative. A bunch of people who tend to control what opinions are "allowed" and which ones aren't. If you have an unpopular opinion, you're basically just shouted down because no one wants to hear it. It's standard operating procedure just about everywhere you go, and sometimes it's organized and malicious, and other times it's simply because many people's normal, knee-jerk reaction to hearing something they don't agree with is to effectively jam their fingers in their ears and go "LA LA LA LA LA I CAN'T HEAR YOU" at the top of their lungs.
The end result is still basically the same: the silencing of dissent in whatever form it comes in.
Now here's the thing: I'm not trying to argue that every single voice deserves to be heard. Some people really are just trying to scream in the dark and contribute nothing meaningful to a conversation. But on the other hand, there are some people who
do try to bring something useful to the table, and this is why I always roll my eyes when the dogpiles start. Because is someone getting dismissed out of hand simply because they're not "saying the right things?" Or because they didn't use the right buzzwords, or whatever kind of trivial offenses people drum up these days to ensure they don't have to listen to someone they potentially won't agree with?
Whatever happened to actually vetting people's arguments? Or is that something nobody bothers with anymore because it's too much work?