Twitter has been hit by a hacker who claims to have gained inside access to the site.
The French blogger Hacker Croll posted more than a dozen screenshots that showed account activities of popular users such as Ashton Kutcher, Lily Allen and President Barack Obama.
The images reveal that the likes of Kutcher and Allen have blocked other Twitter users such as celebrity gossipmonger Perez Hilton, while Obama has blocked 96 Twitter users.
The hacker claimed that he was able to access Twitter's administration panel after stealing a password from a member of staff at the micro-blogging website. He claimed that he reset the employee's Yahoo password after guessing his ‘secret question' and finding the information about his Twitter login credentials inside.
The screenshots attempt to blur most of the sensitive information, including the IP and email addresses of those concerned. However, The Register claimed that although the name of the Twitter admin whose account was supposedly breached was blurred, a simple search suggests it belonged to Twitter employee Jason Goldman.
Graham Cluley, senior technology consultant at Sophos, said: “Although many will blame Twitter for not ensuring that its staff followed sensible policies to better secure critical administrator accounts, let's not forget that the real criminal here is Hacker Croll. They have acted illegally by breaking into these accounts, even if they didn't do anything malicious when accessing the celebrity accounts.”