I agree with Michael Brown that "less secrecy" on the subject of sexual harassment in astronomy would be a good idea. But perhaps not quite in the sense that he intends.
Near the end of the ABC Background Briefing on the allegations of harassment at CSIRO, Brian Gaensler makes some remarks which I find rather disturbing. Hagar Cohen reports that "after three high profile astronomers in the US and the UK were exposed as serial sexual harassers ... Gaensler decided to stop his students working with two of the professors in question." Cohen doesn't say who the astronomers were, but my guess is that at least one of them was Geoff Marcy. Gaensler explained his reaction as follows:
That was an incredible shock. I'd heard rumours about these people, and I knew that they were people that I needed to keep an eye out on around young students, but when you actually hear names, and see the details, and hear about the things they did, it's really confronting that someone who's a very distinguished profound brilliant scientist would actually do these things. [...] I felt that I had no choice but to remove them from the project in both cases. So I wasn't punishing anybody, I wasn't taking the law into my own hands, but knowing that the activities that we were going to be pursuing was going to involve people at the very beginning of their research career, who are enthusiastic and excited and for whom there is a whole range of possibilities, I cannot take the chance of them having a negative experience that could really sour their whole career.
But is it really true that he wasn't "taking the law into his own hands"? It sounds like he made the call. It does not sound like he offered the students the choice of taking the risk. And if the professor in question was in fact Geoff Marcy I think this is a very important question. While some women might have experienced his attention to be inappropriate, as Sarah Ballard did, it's not at all likely that all women would. And even Ballard appears to have mostly benefited career-wise from the association.
In any case, Gaensler appears to have made this call on behalf of at least two women. And it's part of a larger practice of making such decisions for women. Cohen tells us that "Gaensler thinks there's much more to be revealed. In fact he's got a black list." And Gaensler says he's not the only one who is protecting unsuspecting women from sexual harassers. (Do please note the double sense of "unsuspecting" here: these women don't suspect that their future supervisor or collaborator is a harasser, nor do they suspect that their current supervisor is making the decision about whether to take the risk.)
There's many of us who have these informal lists of people to watch out for, either because of rumours or because of things we know first-hand. There's a long list of people who've had investigations against them, or findings against them, or people that you simply do not want your students to be around. [...] I personally know of about 20 senior tenured male astronomers who've had some accusations against them. Whether the accusations are substantiated or not, I can't say, because I haven't participated in the investigations, but I know of about 20 people.
That is, if you're one of Brian Gaensler's students—"particularly [his] female students," as he makes clear—there are about twenty astronomers in the world that, whether you'd like to work with them or not, he will secretly prevent you from dealing with. In some cases, he will do this on the basis of rumors and without knowing "whether the accusations are substantiated or not". Notice that if you're a male student he might let you take the risk. Notice that this gives male students a much greater range of career options and research trajectories. The women will have to make do with whatever path professor Gaensler thinks is safe enough for them to tread.
It's this conception of female agency that I'm always so surprised to see soi-disant feminists promoting. If I were a woman I don't know what I would find more objectionable: the lone harasser or this Secret Order of White Knights, conspiring behind my back to keep me safe from the "inappropriate attentions" of my male professors. I wonder how many women could have discovered an exoplanet under Geoff Marcy's tutelage but were prevented from learning the technique from the master because their supervisor had heard a rumor.