Our philosophy has been that messages belong to the individual posters, and threads belong to the community - not to the original poster (OP). We've had control-freak OPs try to direct the flow of what's said on a thread, and it generally just causes animosity and stifles the creativity of posters. We do allow PermaThreads when there is a specific need for somebody to direct the thread, but that's an exception used only for specific purposes that benefit the entire community.

-Joe-