stop ignored users from posting in threads started by ignoree

[jilly]

Stop ignored users from posting in threads started by ignoree

Here's the scenario
Member A and Member B bicker constantly - nothing against site rules, just annoying and disruptive. So Member A (wisely) decides to put Member B on ignore. However, Member B keeps posting to threads that Member A starts. Member A knows because she sees quoted parts of the thread or other indications of what Member B has said reflected in other responses to her thread. Nothing Member B is saying is against the rules, it just annoys Member A.
Obviously you can't stop Member B from posting to any thread, but could you have an option that stops Member B from posting to any threads STARTED by Member A?