Social networking company LinkedIn said that there are currently 117 million user passwords up for sale on the black market, much larger than its initial 6.5 million estimate, according to CNN Money. The passwords came from a hack on the network that took place four years ago that lifted user data from the site. While LinkedIn is trying to prevent the passwords from being sold, CNN Money notes that it is unlikely anything can be done about it. The problem likely goes beyond LinkedIn alone, said CNN Money, as people often reuse their passwords from site to site, meaning that a large portion of the stolen passwords can probably also be applied to things such as online banking. Needless to say, it may be wise to change your passwords.