What happens when children are stripped from families for normal images?

What happens when teens are caught for normal behavior?

What happens when people are put in prison over drawings?

All three of these have already happened.

And what happens when this gets automated and large entities like the RIAA/MPAA get other illegal content added to these searches?

Basically, all your concerns are about the scope of this, not the essence of it.

And I think it does get to the essence of it, because of just how we quantify something as illegal. The laws are very poorly written, where the worse images possible are treated just as no more illegal than images that are on the borderline of legal (not to mention that the border itself is very fluid, especially when considering artistic images that would be illegal if they weren't artistic but which is left up to a random jury to make a judgment call on).

Congratulations, you've discovered the Slippery Slope argument. https://en.wikipedia.org/wiki/Slippery_slope

"The documents also suggest that Geek Squad technicians report only material they happen to find while doing repairs, rather than actively searching for illegal content on customers' devices."

Oftentimes child abuse imagery isn't hidden at all, it's very likely that Geek Squad employees will come across it at some point purely by accident. It's no different from hitting the report button on a website if you see similar imagery.