Bukkit

So I started a server using this plugin and I'm using Pressure Plates instead of signs. There's a problem where players can left click plates which really defeats the reason why we are using plates in the first place.

After looking through the config file, I couldn't find anything related to this issue.

So if someone could tell me how to disable left clicking I would appreciate it alot.

(I was thinking  maybe disabling clicking perms with pex)