The hackers are a group calling themselves OurMine and recently targeted Mark Zuckerberg’s Twitter and Facebook accounts as well, reports Recode. As for Costolo’s Twitter account, it wasn’t a direct hack. Instead OurMine managed to gain access to a third-party service that allowed tweets to be published to Costolo’s Twitter feed.
looks like an old account from another service that cross posted to Twitter was compromised, not my Twitter acct. I’m on it. Thanks everyone
— dick costolo (@dickc) June 19, 2016