Botnet of 20,000 point-of-sale machines

Not sure how to parse your comment. My original thought had to do with the transfer of hacking technology from extremely sophisticated state-supported groups that is eventually making its way in to the hands of less-sophisticated but equally criminal actors. STUXNET being the A.Q. Khan of the internet world, so to speak.
I wasn’t necessarily attempting to argue that stuxnet was the genesis of these types of attack, rather that someone reverse engineered some of its capabilities and has re-tuned those bits to go after POS machines.