A file containing the encrypted passwords was put online, according to claims by security analysts. It was accompanied by an invitation to the hacking community to help with decrypting them.

 

LinkedIn tweeted that their team was looking into the reports. Users of the website, of which there are 160m worldwide, were advised to change their passwords immediately.

 

Security researcher Per Thorsheim said that the number of users whose details had been released may be even more than 6m, due to repetition of passwords between users.

 

The news follows privacy concerns over LinkedIn's mobile calendar application, which was allegedly sending unencypted calendar entries to LinkedIn servers without users' knowledge, including meeting notes. Concern was raised that telephone numbers and passcodes might be released along with the notes.