It's not necessarily really a blacklist, but when the court case comes up when the employer googles your name... companies like to claim to be pro-equality since they get good press for it, but they're not actually going to put that to any sort of test. Much easier to hire somebody who's not proven themselves willing to stand up for their rights.

It sounds like it was settled before anything went to court, so it's unclear that anything would even come up in a Google search. And yet employers are still finding out somehow.

Word of mouth is powerful.

Oh yeah, it's not remotely legal by any standard whatsoever. The problem is that it's virtually impossible to prove.

In my friend's case, she was at the director level of a large publicly-traded company. Particularly as you approach the top of the that kind of corporate hierarchy, the world becomes very small, and good-old-boy dynamics start to dominate. There's no formal blacklist, of course -- just the opportunity to meet your frenemy from her previous employer down at the bar, where he can confidentially warn you to "watch out for that one: she's a troublemaker". Nothing more needs to be said, and certainly nothing needs to be written.

I suspect that hiring decisions at lower levels will be both more process-driven and better-documented, so it might be more possible to prove the existence of blacklists there (even if it's still far from easy). But near the top of the pyramid, I have great trouble seeing how the punitive legal action can realistically be used to break up the good-old-boy network.

Seeing this play out has actually changed my mind on the necessity of having gender quotas for management and boards. Previously I'd been opposed on vaguely libertarian grounds; now I see it as the only practical way of disrupting the good-old-boy networks that genuinely do a lot of harm. (Society is genuinely damaged -- depriving itself of so much talent -- by systematic bias against women).