Twitter has a problem with online bullying and harassment—especially when it comes to women. And a new study shows that women on Twitter are targeted way more often than we even realize. According to research from Amnesty International, 1.1 million abusive tweets targeting women were sent in 2017—which amounts to about one every 30 seconds.

To reach this conclusion, Amnesty International partnered with artificial intelligence software company Element AI for a research project known as “Troll Patrol.” They asked volunteers to examine 228,000 tweets sent to 778 female politicians and journalists living in the U.S. and the U.K., and then machines used these findings to calculate just how prevalent harassment of women is on Twitter. The researchers found that online harassment “cuts across the political spectrum,” meaning that women of all political ideologies were similarly affected.

However, women of color were disproportionately affected by Twitter abuse. Troll Patrol found that nonwhite women were 34% more likely to be mentioned in “abusive or problematic tweets.” And black women were a whopping 84% more likely to be targeted than white women.

Milena Marin, Amnesty International’s senior advisor for tactical research issued a statement addressing the project and “Twitter’s failure to crack down on this problem.”

Amnesty International noted that it shared these findings with Twitter, and the social media site asked for clarification about what was considered “problematic,” while referencing a “need to protect free expression and ensure policies are clearly and narrowly drafted.”

Freedom of expression is important…but Twitter should care that people are using their platform to harass women and should actively work to do something about it. We don’t think that’s asking too much.