Preventing users from opening closed threads.

[BlueNinjaGo]

We have a small issue with users opening threads after a moderator closes them. Is there any way to prevent users from opening a thread after a moderator closes them?

[BBR-APBT]

Take away their permissions in usergroup options.

[BlueNinjaGo]

Well, I don't mind if they close their own topic... I just mind when they reopen it after a moderator closes it

[Videx]

I'd be really surprised to find out any user could open a thread that was closed by a mod. Even the OP. The relevant permission in the usergroup Manager is:
Can Open / Close Own Threads. If that really means "disregard a mod closed thread and reopen it anyway", then I suppose you'll have to disable it.

Or just create a rule and enforce it.