Ghosts big enough to have a heat signature for an IR missile to track on, apparently.
I don’t think the concept of a transponder or ADS-B out requirement is unreasonable. At a certain point it’s required for drones, and obviously it’s possible to blur the lines between a balloon and a UAS.
Just my personal observation, but working ATC all last week there was a bunch of depicted precipitation on my display, while we were 10+SM CLR, that normally isn’t there. Had to manually turn it off each time I took position, annoying. Now they run software updates and adjustments all the time, but that idea that the filters all got adjusted across the NAS after senior admin got caught with their pants down with the big spy balloons, and now we’re seeing a bunch of stuff that’s been there the whole time that was previously just filtered out, seems plausible to me.