You must change your LinkedIn password as soon as you can.
This week almost 6.5 million encrypted Linkedin passwords have been leaked online - in a Russian forum.
The passwords are encrypted with the SHA-1 cryptographic hash funcion, used in SSL and TLS, generally considered to be relatively secure, but not foolproof.
LinkedIn is taking steps to protect their users, like locking down the accounts associated with the decoded passwords. Read here what LinkedIn is doing.