I believe this was "spoofed" only in the sense that a particular provider/online platform accepted data via an API that was abused to draw this on that platform only. Searching around it seems it was not found if you looked on other platforms, so it might not even have been a crime. I believe they didn't emit any real "signals" just took advantage of an API that should probably be better secured.

At worst it'd be a violation of the site ToS - it's a crowdsourced community data based system, and not any sort of an official, important system. The account doesn't seem to have been banned, so maybe the admins are just rolling with the joke.

> an API that should probably be better secured.

I think the API is secured? The entire premise is that a volunteer creates an account and uploads ADS-B telemetry. Detecting falsified data is a separate matter.