TechCrunch on Tuesday said it had received a compressed file containing 310 documents. Most, said editor Michael Arrington, are mildly embarrassing but are not otherwise noteworthy. A few, however, contain sensitive information such as security passcodes.
Twitter co-founder Evan Williams reportedly has confirmed the authenticity of the documents. Neither Williams nor Twitter responded to requests for comment.
Thomas Landspurg, CTO of Webwag, also said he had been contacted by the hacker, known by the pseudonym "Hacker Croll," and had been given copies of the Twitter documents.
In his blog TomSoft, Landspurg said that Croll claimed to have obtained access to Amazon, Apple, AT&T, Gmail, MobileMe, and Paypal accounts belonging to Williams, his wife Sara Morishige Williams, and Twitter employees Margaret Utgoff and Kevin Thau.
This may explain why Williams on Tuesday evening sent a tweet that said, "Having a bad night."
Landspurg has posted scrubbed screenshots of some of the hacked accounts in support of Croll's claims.
In May, Croll posted a screenshot of Twitter's internal analysis of the worm attack that hit the site in April.
Croll gained access to Twitter two months ago by answering the secret question that allows Twitter users to reset their passwords, the same technique used to obtain access to Alaska Governor Sarah Palin's e-mail account last year.
In an e-mail to Landspurg, Croll reportedly said that he hopes his actions will help people realize that nobody is safe online and that people need to be more careful with their secret questions.
Update: Twitter co-founder Biz Stone has posted additional details about the incident.
Black Hat is like no other security conference. It happens in Las Vegas, July 25-30. Find out more and register.