Toxic and negative discourse can plague social media, but for Margaret Atwood decades as a writer in the public eye has helped steel her to criticism.

"I once got a hate letter from somebody who objected to how much I laughed on a radio show. You're going to get criticism for stuff you do from somebody, no matter what it is," the CanLit icon noted in Toronto Tuesday.

"The thing I say to young writers is: 'Not everybody is going to like you or your book, so toughen up because that is going to happen."

The award-winning author and activist shared the stage Tuesday afternoon with Twitter co-founder Jack Dorsey at an hourlong discussion moderated by TVO broadcaster Nam Kiwanuka.

When faced with criticism on social media, Atwood said she considers several questions.

"Is it accurate? Is it just? Is it based on facts? Are the people lying, which happens quite frequently. People just make stuff up and then attribute it to you... I don't mute or block. I just let them run. Sooner or later it will all come out in the wash," she said.

"Sooner or later everybody will wake up in the morning and they will say 'Margaret was always right,'" she quipped.

The panel discussed a range of topics, returning regularly to the notion of toxic social media behaviour and how the tenor of Twitter discourse has changed over the years (Atwood, on the social network since 2009, says she misses the "jokey" feel of days past).

She also shared a few lighthearted accounts she enjoys, like the observational one devoted to the statue of Canadian poet Al Purdy.

"It will never troll you," she stated. "It observes kindly what is going on."

She also offered an update on her anticipated book The Testaments — a sequel to her influential novel The Handmaid's Tale — that's set for release in September. The novel will be launched in London through a live event that will be streamed to cinemas worldwide.

"I have written [it]. We're in the editing burrow at the moment. I have three days off," she said, noting that she'll incorporate her editors' comments into the next draft of her manuscript.

The sequel comes after the ongoing, "screamingly successful" TV adaptation of The Handmaid's Tale starring Elisabeth Moss and the original book's return to bestseller lists (alongside other dystopian classics) in recent years thanks to the political climate worldwide.

"You write a book like that hoping that it will not come true... 'Here is a possible future. You are possibly heading towards it. Is that where you want to live?'" Atwood said.

"I thought it would diminish, that it would become less true. Instead it became more true."

She also gave the nod to fans who have expanded on the imagery she created, for instance dressing as the novel's scarlet-robed handmaidens to wage silent but powerful protests.

"That has been used to great effect in different countries around the world."