Just remember, above all....DON'T PANIC
To laserlight's point, it seems in the rare occasion that somebody has something useful and positive to add to an old, incorrect thread that has been auto-locked, that they could request special permission from a moderator. Or make a large post count (in the hundreds) a prerequisite to commenting on old threads if that's somehow possible. Honestly, in the 8 months I've been here, I've seen dozens of threads resurrected, and not a single one of these necromancers has contributed anything useful to the thread. The vast majority of the bumps seem to be "I have this homework too, can you email me your solution", and the rest seem to be new comers who think they can build rep points or something by simply rephrasing the already-more-than-good-enough answers given a year ago.
If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
If at first you don't succeed, try writing your phone number on the exam paper.
Splitting the topic doesn't prevent or age a bumped thread.
I've seen threads be split on here before, so I do know.
This is a good suggestion. The basic "prevent replies to old threads" should be quite doable; I will look into it.
I've implemented a very simple version of this. Any still-open thread that hasn't been touched in the last 31 days is automatically displayed as "locked" unless you are a moderator or the thread is a sticky.
Technical details: I was able to add this as a custom vBulletin plugin, making upgrades easy. I also didn't really change the "locked" status in the database (for safety). Everything is dynamically computed, but no additional db queries are required.
Please let me know if you run into any weird behavior as a result of this.
@manasij7479 Oops, that's a good point! Let me see about that...
@CommonTater I don't think that's the case--your profile likely is set to show only messages within the last month. (I ran into this in my testing.)
I've updated the display so that there are no longer links to the reply page for closed threads.