By Steve Evans - CBR security

Twitter, the phenomenally popular micro-blogging site, faces more question about its security procedures after a French hacker claimed he accessed the account of a Twitter employee with administrative rights.

The hacker claimed that this enabled him to access Twitter accounts belonging to US president Barack Obama and singers Britney Spears and Lily Allen. He posted screenshots taken during the break-in on a hacker forum.

The screenshots appeared to show email addresses, mobile phone numbers and information about other Twitter accounts that had been blocked by the user.

This is the latest security setback for Twitter, which has seen huge growth during 2009. Over the Easter weekend the site was hit by a malware attack that resulted in Twitter identifying and deleting almost 10,000 tweets that could have continued to spread the worm.

Graham Cluley, senior technology consultant at security firm Sophos, said: “This is just the latest in a string of security issues at Twitter in recent months, and the website is surely in danger of losing the confidence of its users who will be rattled by yet another breach.

“Just like with the recent Twitter worm outbreaks, this is not so much a case of Twitter raising awareness amongst its many users about sensible online security, but learning a few lessons itself. Careless security by the micro-blogging site could potentially put millions of Twitter users at risk.”

Recent research from Sophos revealed that two thirds of businesses think social networking is a security risk, as IT admins believe that employees share too much personal information via their social networking profiles.