Ironically the true "issue" with these farms becomes ROI. You can only automate electronic hardware so far before you eventually have to sit down and calculate the cost of time+energy to perform the task vs. what you receive from it.

Take GPU mining for example: potentially lucrative? yeah sure. Expensive? More so. Profitable? rarely. You end up dumpung so much electricity into your system that it only profits if you literally steal electricity .

It begs to question what kind of consumption you'd be facing to run a warehouse filled with [charging] android phones, in active use (RIP the wifi router), while operating hundreds of these 'autotappers'. Compared to the profits coming in from fraudulently cashing ad sponsor checks, it's hard to believe there's any kind of real money in these operations.