> I don’t think punishing the steel maker for a gun maker who sold it to a distributor who then sold it to a nut job should be liable for the nut job

Nobody thinks that, because it's ridiculous. This is a false equivalence. Isolated crimes are inevitable, and impossible to solve with any single thing.

But when it comes to genocide, you can stop or at least limit it by going after the suppliers who equip the group with the tools to carry it out. Microsoft is one such supplier, and they know exactly what they're doing. If our government isn't going to do something, an activist shareholder is a decent alternative.