The Twitter account of CEO Jack Dorsey was hacked on Friday by a group called either the Chuckle Squad or the Chuckling Squad, an embarrassing security breach at a time when online privacy and data security at digital companies are under intense scrutiny from the public and the government.

According to reports, including this article by The Verge, the hackers posted racial slurs and bomb threats on Dorsey’s account. The offensive tweets were quickly deleted, with some apparently staying up for about 10 minutes. In a tweet, the Twitter communications team said it was aware of the hack and was investigating.

By mid-afternoon Pacific Time, Dorsey’s @jack account was filled with followers mostly making fun of the incident or using it to criticize the company and its policies. But it appeared the hack had been stopped. Dorsey’s account was previously compromised in 2016 by a company that said it was testing Twitter’s security, The Verge said.