In an interview hosted on Twitter, CEO Jack Dorsey acknowledged that when it comes to tech responsibility, the company still has a long way to go.

Speaking to Recode co-founder Kara Swisher in a 90-minute series of tweets, Dorsey gave himself a ‘C’ on the matter:

Swisher called Dorsey’s response “a cop out”:

While Dorsey largely avoided specifics in his answers, he flagged physical safety as a key issue, citing concerns over harassment campaigns and doxxing, the process by which users are targeted with the spread of personal information.

However, Swisher graded him an ‘F’ on security:

Another drawback of the platform, Dorsey said, was its tendency to act as an echo chamber:

Capping off the interview with perhaps his most eyebrow-raising answer, Dorsey pointed to Tesla CEO Elon Musk as the most exciting tweeter:

The irony, of course, is that Musk has been prone to causing trouble on the platform, sending stocks swinging with tweets about his company and mocking a British cave diver involved in the 2018 Thai soccer team rescue.