Don't know if anyone else has experienced this, but I've received a few emails that appear to be from Marriott, including the normal member inns (Marriott, Fairfield, Courtyard, etc.) logos at the bottom of the email, and they're notifying me of a pending security update to my account and are requesting my account information.
This appears to me to be bogus, as Marriott normally doesn't send out this kind of contact. I've sent notice to Marriott via website contact, so it will be interesting to see if I get a response, and if anyone else has received the same.
If you haven't already done so, you might want to update your privacy information on Marriott (including Insiders) site.