Making a roundup instance read-only

Hello there,

I have a roundup instance, that I want to prevent people from
changing, is there a way to achieve this? I tried Google, but I didn't
find anything suitable. I guess, there ought to be a way with
detectors, but I am not familiar enough with it.

----
from roundup.exceptions import Reject
raise Reject('Read only')
----

Which files should I put that in? Thanks in advance for your help.

Yours,
Kay