Is it possible to limit the number of threads for a single process?

I'm in the middle of this fight with a user. They keep spawning up a custom process, they wrote, using all the threads they can maxing us out and we've asked them to stop. They say ya ya and keep doing it.

We've talked about outright banning them but that isn't flying with management.

So next idea is there a way to set a limit on the number of threads for a single running process?

Then we can just scan for their program and limit it. Should stop them from then crashing our jenkins slaves.