Nestled in the lush green mountains of Central Mexico, next to a sparsely traveled gravel road, few people had reason to wander close enough to hear the loud, mechanical whirring of a clandestine cryptocurrency farm.

What led police to the ramshackle building, suspected of mining virtual coins to launder illicit funds, was not only ⁠the noise but the vast amount of electricity needed to power and cool hundreds of specialized computing units, at levels far surpassing the needs of the small communities scattered around the Sierra Norte…