I'm trying to prevent certain users from posting anywhere on the forum (as a penalty measure) and I thought to create a new group for it. What I did so far was create a new group and set permissions for a certain forum section to Read only. But when I test permissions by adding a user into the group and obtain his permissions I can still see the Post new topic button. I also don't know how to maintain user's access level to certain sections (not all members have access to all sections) but prevent posting everywhere.
A phpbb3 user group to prevent posting
phpbb