Do you really think they test all these units before they ship them? I seriously doubt they test any. A few random boards may be tested somewhere in the process, but that's probably it. To actually mine coins with them before shipping to the customer is an entirely different matter. Building mining farms with PH power is an entirely different matter too. Maybe people need to start demanding some proof that the units haven't actually been used to mine with. Maybe one of the electronics people around here could speak to the idea of a counter chip or something.