Thousands of women are identifying themselves as victims of sexual harassment or assault following a call to action led by actress Alyssa Milano in the wake of Hollywood mogul Harvey Weinstein's downfall over allegations of sexual misconduct spanning decades.

Milano suggested on Sunday that women who have been sexually harassed or assaulted post the hashtag #metoo on Twitter. A flood of messages has erupted across Twitter as well as Facebook and Instagram.

The actress said she got the idea from a friend, who told her such a tweet "might give people a sense of the magnitude of the problem."

The call to action quickly trended, with notable names like Lady Gaga, Monica Lewinsky and Rosario Dawson alongside a massive wave of women — and men — identifying themselves as victims.

Others shared personal stories. 

"Being raped once made it easier to be raped again. I instinctually shut down. My body remembered, so it protected me. I disappeared. .metoo," actress Evan Rachel Wood wrote as part of a series of tweets on her experience.

"Sharing my stories and feeling less alone really helps. So thank you for listening."

Some women weighed in with stories of assaults while in the military, gang rapes and catcalls.

Also tweeting in support was Milano's former co-star on TV's Charmed, Rose McGowan, who has accused Weinstein of raping her.

A similar social media campaign is playing out on Instagram among models who are sharing stories of abuse and harassment in the fashion industry.

Model Cameron Russell put out a post four days ago offering help to models and has been deluged with responses. She has shared many on her Instagram feed, blacking out identifying factors but leaving the stories otherwise alone. Some women who reported unwanted touching and worse said hearing from their sister models has brought long-buried recollections to mind. 

The effort has launched the hashtag #MyJobShouldNotIncludeAbuse.

Further actions against Weinstein

Milano called the Weinstein allegations "disturbing" in an essay last week, but added that the issue was complicated for her because she is friends with Weinstein's wife, Georgina Chapman. Fashion designer Chapman has filed for divorce since the revelations.

In another tweet that links to a blog post, Milano added: "While I am sickened and angered over the disturbing accusations of Weinstein's sexual predation and abuse of power, I'm happy — ecstatic even — that it has opened up a dialogue around the continued sexual harassment, objectification and degradation of women."

Weinstein-Allegations Timeline

More than three dozen actresses have now come forward with allegations of sexual harassment or assault against Harvey Weinstein, including (top row from left) Asia Argento, Rosanna Arquette, Jessica Barth, Cara Delevingne, Romola Garai, Judith Godrèche, Heather Graham, Angelina Jolie, Ashley Judd, Rose McGowan, Léa Seydoux and Mira Sorvino. (Associated Press)

Meanwhile, French President Emmanuel Macron said on Sunday he has "started the procedures" to revoke Weinstein's Legion of Honour award over the multiple accusations of sexual assault and harassment against him. Another American is among the few people to have lost the distinction: disgraced cyclist Lance Armstrong.

Macron also said he wants to speed up the legal procedures for investigating and prosecuting sexual harassment to encourage more women to come forward. French actresses are among those who have accused Weinstein of sexual wrongdoing.

The Oscar-winning producer was indefinitely suspended last week from the British Academy of Film and Television Arts and expelled as a lifetime member of the U.S. Academy of Motion Picture Arts and Sciences on Saturday

On Monday, the Producers Guild of America voted unanimously to institute termination proceedings for Weinstein on disciplinary grounds. The guild's national board of directors and officers said he has an opportunity to respond before a final decision is made on Nov. 6.

The organization also instituted an anti-sexual harassment task force to research and propose solutions to what it calls a "systematic and pervasive problem requiring immediate industry-wide action."

The guild has terminated memberships in the past for failure to pay dues, but Weinstein is the first to have been voted for expulsion on disciplinary grounds.

Police in New York and London are investigating allegations of sexual assault against Weinstein, who through a spokesperson has denied all allegations of non-consensual sexual activity.