The full letter reads:
Turbine is concerned that a third-party recently may have attempted to access forum account information. There is no indication at this time that your account was modified or compromised. For your protection we suggest you change the password to a unique, hard to guess password not associated with any other sites or services. If you changed your password after October 11th, then you can disregard this message.
To change your password, please follow these steps:
Go to https://myaccount.turbine.com/ and click on “Forgot your password?” You may also click this in the game launcher.
Follow the instructions on how to recover your password. A new password will be sent to this e-mail address.
Once you have received the password reset e-mail, change your password. Please remember to use unique, hard-to guess passwords that are not associated with other online services or sites.
Turbine takes your account security seriously. If you have any questions, please feel free to contact us at https://support.turbine.com/. You may submit a new inquiry to our Customer Service team, and they will be able to assist you further.
Better safe than sorry, it’s advisable to change passwords now.