How to deny permission to close own threads?

[Goldoff]

I have an user posting conflictive content and then, as OP, closing the thread to avoid being responded. I want to keep the thread open in order the others can post their own points of view, but this user keeps closing it every time I re-open it.

I can see options to limit or deny editing or deleting own posts, but not closing them.
Is there something I have missed in the ACP?

Thank you in advance for any help

 

[Mr Lucky]

If a user can close a thread, then that could only happen if you gave them permissions to do so, and it is in fact a moderator permission.

By default registered user group has no permission to lock a thread whether OP or not. Perhaps you have an addon that gave them that permission.

 

[Goldoff]

If a user can close a thread, then that could only happen if you gave them permissions to do so, and it is in fact a moderator permission

Oh, I just realized this is made through an Andy's add-on I installed some time ago.

Sorry for bothering you, and thanks for the tip