[PunchyHamster]

There is no security within ADS-B. All you need is directional antenna pointing at receiver (if you just want to fuck with website, not cause mass panic in the nearest airport tower), there is no encryption or other form of authentication in the messages.

[ryandrake]

The security in question is the ADS-B exchange's web site's security, not the security of the ADS-B system. It's unlikely this vandal even has an antenna.