Motorola is disabling Android phones purchased through unauthorized sellers in Mexico

https://lemm.ee/post/9517457

Motorola is disabling Android phones purchased through unauthorized sellers in Mexico - lemm.ee

Devices purchased abroad for use in Mexico, though, will apparently not be disabled

How do they know where they purchased it?

Imei
That might say where the phone is intended to be sold, not where they purchased. As I understood it, Motorola wants to ban foreign phones purchased in Mexico. How can they differentiate them from foreign phones purchased abroad?