Niantic tried to implement anti-cheat measures around Pokemon Go. They hashed a lot of data available to the client and the phone. With some math/ML it's easy to do outlier detection and find the hacked/spoofed clients based on their GPS/gyroscope/accelerator/... data. It took ~4 days for the community (some bot devs, mostly map / tool developers) to figure it out, although the scene has never been the same since.