With the exception of the originator of the New Question who should be able to comment on any replies connected to his question, we have noticed that any user with ACL permission to post comments can comment on other uses' replies.
1. User A creates New Question
2. User B replies New Question
3. User C comments on User B's reply
This should not be the case, user C should only be able to comment on replies he posted. Only user A who created the Question should be able to post on user B and user C's reply.
How can we ensure that only the user who post the New Question and user who posted the particular Reply are able to comment on that reply?