Prime Minister Justin Trudeau pointed to his government's policy efforts to discourage sexist harassment today, after CBC News disclosed the astonishing volume of online vitriol aimed at Alberta NDP Premier Rachel Notley.

"We need to continue to stand strongly and firmly against harassment, intimidation and violence in the workplace, in our communities, in our homes," Trudeau told a press conference in Cambridge, Ont. on Friday.

"That's why this government has been so eager to put forward strong legislation and demonstrate that there is zero tolerance for the kind of hateful rhetoric that, unfortunately, we do see too often around us."

Trudeau was responding to a CBC News report this morning that revealed Notley has received at least 11 death threats in the three years she's been premier of Alberta.

Not all of the threats against Notley happened online. One of the incidents described in the 386 pages of "occurence summary" reports obtained by CBC News from Alberta Justice was especially macabre: on Jan. 31, 2017, Notley's office was alerted by an insurance company specializing in pre-planned funerals that a funeral home had received a completed application in the premier's name — for her own funeral.

McKenna calls out social media

Environment Minister Catherine McKenna called on social media platforms to do more to discourage threats of violence against politicians.

McKenna told reporters Friday morning that she has spoken with Twitter about tackling trolls who send violent and aggressive messages over social media.

"I had the opportunity to sit down with Twitter and to have a discussion," she said. "I certainly think that they should be looking into what's happening on their platform."

Death threats, violence & hate speech aren’t part of the job!<br>Terrible attacks on Alberta <a href="https://twitter.com/abndpcaucus?ref_src=twsrc%5Etfw">@abndpcaucus</a> Premier <a href="https://twitter.com/RachelNotley?ref_src=twsrc%5Etfw">@RachelNotley</a>: we must stand up against <a href="https://twitter.com/hashtag/VAW?src=hash&ref_src=twsrc%5Etfw">#VAW</a> in every workplace.<br><br>I’m on <a href="https://twitter.com/PnPCBC?ref_src=twsrc%5Etfw">@PnPCBC</a> 5pm eastern <a href="https://twitter.com/CBC?ref_src=twsrc%5Etfw">@CBC</a> <a href="https://twitter.com/hashtag/canfem?src=hash&ref_src=twsrc%5Etfw">#canfem</a> <a href="https://twitter.com/hashtag/cdnpoli?src=hash&ref_src=twsrc%5Etfw">#cdnpoli</a><a href="https://t.co/jiRN69E2gT">https://t.co/jiRN69E2gT</a> —@s_malcolmson

McKenna also said Facebook and other social media platforms share a responsibility to address online threats.

"We need to make sure that they are being used in a way that is in accordance with the law and also in a way that allows us to have conversations," she said.

While she didn't go into details about her conversation with Twitter, she pointed to the frequency of online threats targeting female politicians like Notley and Ontario Liberal Premier Kathleen Wynne — and wondered aloud if a hostile online environment is driving women away from careers in politics.

The alt-right targets women more than men. There's no question. - Green Party Leader Elizabeth May

"It's as much about the girls and women who are looking at what's going on, and also the boys and the fathers who are wondering if it's OK for women to go into politics," McKenna said. "I certainly think it is, but we have to be vigilant."

Ontario also has introduced policies on harassment, Wynne said at today's press conference alongside Trudeau. She referred to funding for sexual assault and victims services and public education campaigns.

"What we are dealing with in terms of what's happening in Alberta is happening everywhere, you know," she said. "Misogyny is a reality that is something that we have to acknowledge."

Politicians respond to threats

Green Party Leader Elizabeth May told CBC that she has received aggressive messages throughout her career — including what she called one "very specific" and "credible" death threat about nine years ago.

Female MPs on the death threats they've faced 0:40

"There are messages that are designed for political gain and the alt-right targets women more than men. There's no question," she said.

"I can't take them seriously. If they're highly specific, I contact the RCMP."

I admire and stand with these courageous women who are working hard to build strong communities. These threats are deplorable but they don't reflect majority Albertans who are embracing and welcoming. <a href="https://twitter.com/hashtag/ABLeg?src=hash&ref_src=twsrc%5Etfw">#ABLeg</a> <a href="https://twitter.com/hashtag/yeg?src=hash&ref_src=twsrc%5Etfw">#yeg</a> <a href="https://twitter.com/hashtag/yegmedia?src=hash&ref_src=twsrc%5Etfw">#yegmedia</a> <a href="https://t.co/1BhrgSWK95">https://t.co/1BhrgSWK95</a> —@SohiAmarjeet

At a time when social media platforms are under scrutiny over privacy breaches and cyber threats, governments are looking to social media companies to do more to monitor and prevent online abuse.

"I think there could be more done by social media to police the sites," May said. "In the old days, a newspaper would not publish vile commentary. Twitter and Facebook are publications. They should have the same standards and rules, but they don't."

Last year, the House of Commons Status of Women committee looked at what Facebook and Twitter are doing to mitigate online violence and threats, NDP MP Sheila Malcolmson said.

"We're pushing for corporate leadership to make these platforms safe," she said. "If they don't do their job, then we'll be pushing Parliament to do what it can."