If you have an account with LinkedIn you should read this email. The social network giant has had a major security breach in their password database and a file with 6.5 million hashed passwords appeared in a forum based in Russia. The posted file does not include user names or any other data, however that may mean that the hacker simply did not post that part of the stolen information.
It is advised that you change your LinkedIn password
Read this blog post at LinkedIn on best practices for your password