Following Elon Musk’s takeover, Twitter was the target of a coordinated trolling campaign, according to Yoel Roth, the company’s head of safety and security. In a thread spotted by The Guardian, Roth said late Saturday that Twitter was working to stop an “organized effort” by trolls to make people think the company had weakened its content guidelines. “Bottom line up front: Twitter’s policies haven’t changed. Hateful conduct has no place here,” Roth said, adding the company had seen a “small number of accounts” post “a ton” of tweets that included derogatory language.

In one instance, Roth says the company saw just 300 accounts post more than 50,000 tweets using the same slur. “We’ve taken action to ban the users involved in this trolling campaign – and are going to continue working to address this in the days to come to make Twitter safe and welcoming for everyone,” he wrote.

The news of a coordinated trolling campaign comes after a handful of research groups found evidence of bad actors trying to test the limits of Twitter. On Friday, the Network Contagion Research Institute tracked a 500 percent increase in usage of the n-word. The nonprofit linked the increase to posts on sites like 4chan, where users were encouraging each other to post hateful content.

On Friday, Musk said Twitter would not make any major moderation decisions until the company had the chance to form a council with “widely diverse viewpoints.” Before taking control of the company, Musk had said he wanted to do away with permanent bans, noting he would “err on the side of, if in doubt, let the speech exist.” More recently, he floated the idea of allowing users to split off into different sections of the platform where they could add content ratings to their tweets.