Hello,
would it be possible to have person to enter site and be automatically registered.
With random username, something similar that the nickname extension does.
This would allow him to post with unidentified ID that can't be traced to profile etc.
So this is anonymous posting. But there actually is profile, so moderating team can ban him etc.
If the person leaves and comes back later, cookies remember him?
If he decides to register, he can do that, but it is not necessary.
If he clears browser cache and joins back, he will have "new account" based on new cookies.
Is this possible to do? I am not coder but this is how I think I would do it.