It is ludicrous that you have not addressed a security leak such as this.
If a person sync's their phone with your system and then sells it or has it stolen or, if somehow someone else is able to log into sync one time, the account user cannot delete that mobile device!! Incredible!!! Totally unacceptable. Completely blows the concept of Google Sync and Google Chrome out of the water.
What bone-head engineer/programmer screwed this on up and won't fix it.