A recent article in Taiwan and a related report by F-Secure raised privacy concerns by stating that Xiaomi devices are sending phone numbers to Xiaomi's servers. These concerns refer to the MIUI Cloud Messaging service described above. As we believe it is our top priority to protect user data and privacy, we have decided to make MIUI Cloud Messaging an opt-in service and no longer automatically activate users. We have scheduled an OTA system update for today (Aug 10th) to implement this change. After the upgrade, new users or users who factory reset their devices can enable the service by visiting "Settings > Mi Cloud > Cloud Messaging" from their home screen or "Settings > Cloud Messaging" inside the Messaging app - these are also the places where users can turn off Cloud Messaging.
We apologize for any concern caused to our users and Mi fans. We would also like to thank the media and users who have been sending us feedback and suggestions, allowing us to improve and provide better Internet services.
Fast response, but it's exactly this kind of shitty behaviour that especially a Chinese company simply cannot afford out here in the west. If Microsoft, Apple, or Google does something like this, they'll have armies of defenders and a huge PR department to solve it. Upcoming Chinese companies are generally much, much leaner and do not have that at all.
In any case, you're generally much better off with a custom ROM anyway, and this just yet another reason.