The wild part for me, though, is when I basically played the basic Greensleeves on the lute from memory in a livestream, then slipped into playing Francis Cutting's version (the best, IMO, the elegance of the compound meter is just badass) after the first playthrough, again by memory, I was copyright struck after the fact twice, with a strike for each, one after the other.
TBF the proper way of doing it would be to improv it into your own direction, which I did afterwards and didn't get struck for, but it's just crazy to me how much the recording industry tries to clamp down on anyone performing anything even vaguely sounding like a preexisting recording. I contested the strikes, largely standing on principle that I was doing the performing myself and that the music itself was ancient and they were dropped.
Define container; reasonably, a room could be defined as a container. A container of what? And furthermore, define empty! Knowing when something's "empty" has all kinds of applications. That and teleporting, even a few inches could be incredible, especially dependent on how often/quickly you could do it. 3 & 7, hands down