I mean, if you've been brainwormed by the idea that FAANG (what, literally all of them?) are _strongly net negative_ compared to the most realistic counterfactual that would spring up in their absence, and not only that, but that engineers working there are therefore morally tainted, then sure.

But no, I don't work for FAANG. I could say the same about any of my previous places of employment, none of which were even tech companies (unlike the current place).

But let's put all that aside - how does refusing to hire someone _leaving_ one of those companies improve the situation? Are you trying to establish an equilibrium where it becomes more costly in expectation to join one of those companies, because it might be harder to find another job afterwards? Good luck, I guess! I don't expect you'll move the needle much, especially given that there'll be quite a few people actively working against efforts like that.