A German-Israeli satirist has painted abusive tweets in front of Twitter’s office in Hamburg in an effort to draw attention to what he says is the company’s failure in combating hate speech. The BBC reports that Shahak Shapira reported 300 incidents of abuse over six months, but Twitter responded to just nine, claiming those instances did not violate the social-network’s terms of use.

“The statements I reported weren’t just plain insults or jokes, but absolutely serious threats of violence, homophobia, xenophobia, or Holocaust denial,” Shapira says, in a YouTube video. Shapira, who is Jewish, said he also reported 150 comments to Facebook, and 80 percent of those were removed within a few days.

In the video Shapira can be seen stenciling tweets with chalk paint in front of Twitter’s German office. He chose 30 tweets in total, creating stencils from them, and traveled to Hamburg for the project. The tweets include “Retweet if you hate Muslims,” and other offensive material. “If Twitter forces me to see those things, then they’ll have to see them too,” says Shapira.

Twitter has been struggling to tackle a bullying and abuse culture it is trying desperately to diminish. The company noted last month in a shareholder letter that there’s been a 25 percent reduction in reports of abuse at the same time the number of abusive accounts it takes action on has increased by tenfold.