McLean, VA (written by Zach Cohen/USA Today) -- Last.fm says it is investigating the leak of some user passwords, according to the music recommendation service's blog.
Last.fm is encouraging users to change their password as soon as possible and said users should avoid emails that ask to update their settings or change their password.
It's unclear how many passwords were leaked or who hacked into Last.fm's system.
Earlier this week the professional social network LinkedIn confirmed that about 6 million of passwords had been stolen. Shortly after, eHarmony, an online dating site, said about 1.5 million passwords had leaked.
Typically, passwords were leaked in the form of "hashes," so they are encrypted. But once hackers break through that encryption, they can steal information relating to an account using that password, according to PC Magazine.
As a matter of safety, anyone with an account on a site targeted by hackers should change their password both in that account and on any account anywhere where the same password is used.