Are these legal?
Does anyone have experiences with blacklists from the hiring side? I have never seen such a thing. How are they shared? How does one know if someone is on the list for a good reason? How does it scale?
Another method is that hiring managers at different companies may have good relationships with each other. Not competitor companies, but adjacent. They may call around and ask about a candidate. You can never say anything negative about a candidate; that's just asking to be sued. I think many (most?) companies have a strict policy that you can only say if a candidate is eligible for rehire or not, nothing else. So you talk in vague generalities, never about the candidate, only about the general hiring process. Something like "Company policy prevents me from giving any recommendation whatsoever, so my advice is that you should always be very careful in your hiring process" versus "Company policy prevents me from giving any recommendation whatsoever, but an effective hiring process can yield great employees." You might argue that a judge would see right through that and say it is obvious which candidate you are recommending and which you are panning. But it's so nonspecific that your lawyer can strongly push back, should it come to that.
Would that change anything ? Of course those lists wouldn't be broadcasted publicly.
> Does anyone have experiences with blacklists from the hiring side?
There's that "over 40" list I have seen once when I was on the hiring side. There's also that "good gender" list which benefited me when I was on the hired side once.