Plus, I'm pretty sure it's impossible (or not simple).
Possible, yes. Simple, definitely not. First you would have to check the timestamp of the last reply, then compare it to a current timestamp. If it is older than two weeks, you need to have it lock the topic, which means that the Java or Python, or whatever code, has to be compatible with html. Then you need time to define the functions and check if it works. Plus with new threads you would have to make sure it checks those too. Then optimization of skipping already locked topics. I would estimate probably a three month development period for a beta version. Maybe 7 months for alpha.
So Chris is right, possible? Yes. Practical? No.
So unless you want to write it
SAFollis , I doubt any staff will.