Just because I don't often get a chance to talk about this, I'll mention that there was a malfunction/accident/bug that caused what you might call spoofed signals to go out around Long Island and New York. Really interesting case where it seems that an FAA system wasn't handling magnetic declination correctly, which led to it generating false TIS-B targets that were rotated 13 degrees from real aircraft positions, from the radar antenna point of view: https://x.com/lemonodor/status/1508505542423064578

(TIS-B is a system that broadcasts ADS-B-like signals for aircraft that are being tracked by radar but either don't have ADS-B Out or otherwise might not be picked up by other aircraft with ADS-B In, e.g. maybe they're at a low altitude.)

There have been a couple other incidents with the TIS-B system. E.g. this apparent test near Dallas in 2022 that generated dozens of false targets in an interesting pattern: https://x.com/lemonodor/status/1481712428932997122 There was a similar incident around LAX several months later.

whoa, i saw your initial tweet about this, but never saw your follow up that confirmed the magnetic declination association. the convergence back to the ground radar is brilliant. nice find.

Wow, that would appear to have some potential for bad stuff to happen.