Half of all misogynistic tweets posted on Twitter come from women, a study suggests.

Over a three-week period, think tank Demos counted the number of uses of “slut” and “whore” as indicators of misogyny. It found evidence that 6,500 unique users were targeted by 10,000 abusive tweets in the U.K. alone.

The research comes as five U.K. MPs—Yvette Cooper, Maria Miller, Stella Creasy, Jo Swinson and Jess Phillips—launch their Reclaim the Internet campaign, in response to growing public concern about the impact of hate speech and abuse on social media.