CyanogenMod team has announced that the CM accounts are now live and will be available as a part of the next CM 10.1 or 10.2 nightly builds for your device. If you are hearing about CyanogenMod accounts for the first time, it is an optional feature for CM users and includes some benefits like ability to remotely find your CM-powered device or initiate a remote wipe of your phone in-case of theft.
The features of CM accounts are limited at this moment but we can always expect to see more features in the coming months like ability to sync ROM settings etc.
To add a CyanogenMod account on your device, go to Settings > Add account > CyanogenMod and create an account or log in with your existing account credentials. You can use the Find and Wipe functionality via: https://account.cyanogenmod.org/login.
You can read more about CM accounts at this link. If you are worried about the security of your account or your phone in-case something happens to CM servers or other scenarios, this comment made by Chris Soyars on Google+ should clarify that.