People say go change your LinkedIn password, I would advise you differently. Until LinkedIn has explained what has happened, it may be safer not to change your password immediately. Either your password is already out there and in danger or it isn't, but changing your password may expose you when you weren't before. Ensure LinkedIn has closed whatever hole allowed the passwords to be stolen in the first place. As soon as that happens you definitely should change your password there. In the meantime, if you used a similar password pattern elsewhere, you should consider changing those password now, especially if you used the same email address and password pattern for facebook or google+.