Story highlights Actress tweeted asking women to respond

#MeToo began trending on Twitter

(CNN) Two simple words became a rallying cry on Twitter to stand against sexual harassment and assault.

"Me too."

Social media was flooded with messages Sunday, mostly from women, who tagged their profiles to indicate that they have been sexually harassed or assaulted.

On Sunday actress Alyssa Milano tweeted a note that read "Suggested by a friend: If all the women who have been sexually harassed or assaulted wrote "Me too" as a status, we might give people a sense of the magnitude of the problem."

"If you've been sexually harassed or assaulted write 'me too' as a reply to this tweet," she wrote.