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

Milano passed along a suggestion from a friend on Sunday that women who have been sexually harassed or assaulted post "me too" to "give people a sense of the magnitude of the problem."

The campaign quickly trended on Twitter and Facebook, with notable names like Lady Gaga, Monica Lewinsky and Rosario Dawson 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."