The group took credit by posting a brief message on Williams’ Twitter account. “Hey, it’s OurMine Team, we are just testing your security, please send us a message (firstname.lastname@example.org),” they wrote.
OurMine is the same group that recently compromised Mark Zuckerberg’s social media accounts.
Twitter said it does not comment on individual accounts, but noted in a statement: "A number of other online services have seen millions of passwords stolen in the past several weeks. We recommend people use a unique, strong password for Twitter."
This is the latest in a string of high-profile attacks, including Drake, Lana Del Rey, Zuckerberg, Katy Perry, and even the NFL.