​The world has been plunged lately into a much-needed conversation about the appalling behaviour of some powerful men toward women.

And how the mighty have fallen: Harvey Weinstein kicked out of the Academy of Motion Picture Arts and Sciences; U.S. Sen. Al Franken, Rep. John Conyers, and Rep. Trent Franks all resigning from Congress; journalists Charlie Rose, Matt Lauer, and Mark Halperin all shown the door by their employers.

All of these men and others exhibited everything from crude behaviour to out-and-out sexual assault and have justifiably faced the consequences.

But perhaps it’s time to shine some light on other kinds of unacceptable behaviour by men — behaviour that seems to be having a chilling effect on women expressing themselves.

Over the years as we’ve been trying to book female guests to appear on The Agenda, women have given us numerous explanations as to why they often haven’t been keen to accept our invitation. Having other obligations, including family commitments, tops the list. Concern about not being “the right guest” for the topic also shows up, as does not feeling or looking one’s best at the moment in a world that still judges women heavily based on their looks.

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But an email exchange the other day with a York University professor pointed me to another disturbing reason why some women just don’t want to appear on television, even on programs as civilized as we aim to be.

A couple of weeks back, I went looking for university professors to discuss the Wilfrid Laurier University freedom of expression controversy for an upcoming edition of The Agenda. I reached out to Alice MacLachlan, an associate professor of philosophy at York University, who’d been on the program twice before, and whom I’d hoped to convince to come on yet again.

As it happened, MacLachlan had just had a baby and was unable to accept our invitation. But then she confessed that even if she had been available, she’d probably take a pass on appearing anyway. I wondered: Had we not provided a welcoming forum the last time she was on?

As it turns out, that wasn’t the problem. The problem for MacLachlan came after the show aired.

“I received a barrage of hate mail, including multiple threats of rape and violence, including violence to my family, after my last appearance on your show,” she emailed me. “I still get the odd hateful email or message to this day. I have found myself quite effectively silenced by these attacks.”

For the record: I have MacLachlan’s permission to share the contents of our email exchange. When I learned of her predicament, I was shocked and wanted to expose this unacceptable behaviour by some cowardly men.

We know that both men and women are capable of acting viciously when hiding behind the screen of an anonymous e-mail address or Facebook account. But the degree of misogyny and threats of sexual violence that MacLachlan and other women sometimes receive following media appearances indicates the vast majority of these online abusers – and abusers are what they are – are men.

Frankly, we journalists already have enough difficulty convincing too many potential female guests to share their views on TV because of the reasons listed above and more. We also are fighting a basic numbers game — in many sectors we cover on our program (including politics, economics and technology) male experts from academia and other established institutions outnumber (and sometimes vastly outnumber) female ones, and therefore women are simply harder to find and book.

Thanks to the work of Shari Graydon’s Informed Opinions organization, we’re turning the corner on not only finding more female guests, but convincing them to come on the air as well. For example, rather than assuming that universities are the be-all and end-all for expertise, we’re much more likely to also reach out to smaller, newer organizations that have great people working for them but might not be as male-dominated.

But now, it seems, we have yet another obstacle to overcome, thanks to some gutless, insecure male viewers, who are happy to throw insults from a distance but no doubt couldn’t match wits with our guests in person.

“Some of us just don’t have a high tolerance for a daily diet of rape threats,” MacLachlan emailed. “My experience on The Agenda has significantly altered the readiness with which I will speak in any public forum.”

While I, of course, totally understand MacLachlan’s position, I think it’s a shame. The whole point of The Agenda is to host a marketplace of ideas, then provide the environment in which to have intelligent conversations about those ideas. Diversity of opinion is essential to our business. If some of those opinions are no longer available to our viewers because of yet more bad behaviour by men, we all lose.

Sadly, MacLachlan isn’t the only female guest to have experienced such vicious blowback. The associate chair of graduate studies at the philosophy department at the University of Waterloo, Shannon Dea, was a guest on that recent Agenda program. She confirms that she, too, received some awful responses to her appearance on that show and has given me permission to share one.

"[We] will make you regret the day you were born,” this particular tormentor emailed. “We know where you work now. You need to give up your job ... If you don’t we will make you regret it for the rest of your life.”

Dea says over the years, she’s received numerous abusive tweets, emails, letters, and phone messages, many of them personal, some of them violent.

“I'm used to it, and I'm committed to engaging with public irrespective of the response that I know I'll get,” she says. “But I have women (and racialized and trans, etc.) colleagues who don't engage with the media because they find this kind of response way too stressful, upsetting, and disruptive of their lives and work. And I don't blame them for this one bit.”

(To underline Dea’s point that this kind of hate gets directed toward not just women but other marginalized people as well: Rinaldo Walcott, a University of Toronto professor who appeared on the same program as Dea and who is Black, faced multiple nasty attacks on social media for what he said on TVO.)

Graydon confirms she hears these horror stories often.

“But gutless trolls who succeed in bullying some women into silence need to understand that for every one of us they stifle, half a dozen more, enraged by their contempt, are motivated to speak up to change the world,” she adds.

Incidentally, MacLachlan couldn’t have been more supportive in echoing Graydon’s comments, saying that she did know other female professors who were prepared to risk the blowback and come on our program. She then concluded our email exchange with “Best wishes,” which was generous of her, given everything she’s been through.

Add this sorry tale to the already too long list of woeful behaviours that some men simply have to stop.

Cut it out, you idiots. You’re ruining things for the rest of us who actually aren’t afraid to engage in a civilized fashion on a wide range of interesting, provocative ideas.