The Verge has reported that about 6.46 Million, in fact 6,458,020 passwords of the famous Networking site LinkedIn have been leaked online. All these passwords are believed still to have an encryption and are floating around the Web to download. The username pertaining to these passwords are unknown still but there are big
chances that your account maybe one of them, so hurry up and change the password.
The report was first published out of this Russian site and people thought it was yet another of those online gimmicks untill it was widely reported across twitter that people faced issues with their LinkedIn accounts. The Chief Research Officer of F-Secure confirmed that the list is “a real collection” and he was “guessing it’s some sort of exploit on their [LinkedIn's] web interface, but there’s no way to know. I am sure sure LinkedIn will fill us in sooner or later.”
However, it would take a lot of time to decrypt such a large number of passwords so you have little to worry about but as a precaution it would not harm if you changed your password. It is not like anyone is accessing your account details but like they say prevention is better than cure. LinkedIn on their part have promised that they are investigating the issue and would get back with the findings very soon.