Did you know that you can change the title of the topic you're responding to, for the response post you're making?
Say there's a topic: "Matthew is a jerk!" and I want to respond to it. To prevent "Matthew is a jerk!" from appearing in the main threads listing, and propagating that title further, I could change the title to "Matthew is just fine!" as I make my response post. Then, for that post, the title will be changed. And if anyone just lazily hits "Reply" to that thread after me, and makes a response, guess what title will be used? "Matthew is just fine!" -- MINE. Now if someone replies to the ORIGINAL post in the thread, the original title will be used. But even then, the responder COULD change it if he or she wished.
And that can be done by ANY member, not just moderators. Just make sure you do it BEFORE you create your reply post. I don't know if members can modify titles after the fact.