I'm wondering why aren't the inactive threads auto locked and moved to archive? For example some threads which don't have new replies for maybe over a year should be locked and moved to archive.
But there are legitimate reasons for posting comments to old threads. Some have already been mentioned here. I would therefore instead suggest implementing a restriction based on user rank. I’m thinking that would at least take care of newbie throwaway accounts posting garbage in dead threads. Auto-locking sounds like a good idea. If this was done, then you wouldn't need to archive the thread.
I can think of no good reason why an old thread should be bumped. Most forums suggest that the approved method of adding updated comments to an old thread is to link to it, and post the updated information in a new thread. This saves readers from scanning through a load of outdated posts tht are no longer relevant.
