Don't know. Don't care. They're obviously not dangerous (as long as they don't disrupt airways) and it's also hilarious that they're FAA compliant (green and red lights on the wings, white light on the front). It's either the US military and that's why "they" won't tell us or shoot them down, or it's a private entity screwing with everyone and "they" won't tell us or shoot them down because they actually don't know and they have been very little bother to people besides the social media bullshit. Also what do you mean nothing tangible about them?