1. This appalling story of further PayPal misbehavior, combined with the pretty wild New Yorker profile in which a founder of the company is shown to be a mad libertarian and something of a supervillain, made me think it would be interesting to construct a story around the conceit that the company (in the story: a thinly-disguised analog) exists mainly to do disruptive social engineering experiments, or, alternately, to track down and destroy magical artifacts. Or both! Although you would then need more of a story to work that detail into.
2. This was, I think, covered pretty well in the pulps between about 1900 and 1950, but maybe we can get somewhere new with it: what if all the little optical mind tricks, like the square that seems larger than the other square and the spiraling shape that superimposes itself, are basically like Hero’s aeolipile: demonstrations of an underlying process that just needs a bit more engineering to be turned into something fundamentally world-changing. This could I guess fairly easily get kind of stupid.