It will be easily solved using extra criteria (Daily Posts, Likes, messages, etc) in specific threads.
ie, -You open a thread and you specify that users need to have at least 10 likes to see that thread.
-some user give you problems, then you decide ban that user and you selelect:

the user will think, ok, I'll log out and take a look... but there are criteria applied 
then the user will see this nice message:
You must be a logged-in, registered member of this site to perform this action.
Would be awesome have this feature in the future in Xenforo.