In real world, privately owned public places like mall have their own rules and security (often with lethal weapons). They reserve the right to kick you out, use force if believe you are a present threat, and may block you from coming back in future.

Spam.

Edit: here is Russ Allbery's legendary rant from 22 years ago on the subject. He is effectively arguing with himself in the preface, saying he doesn't want anyone banned from USENET, but I agree with the ranting Russ in the body.

Due process is not a concept internet communities have really ever understood, outrage and reaction rules the internet, not calm, dispassionate logic or process