[jsulak]

I'm from FlightAware...

Our network ADS-B ground stations is one of our fastest-growing data sources, but we also get data from the FAA, other national aviation authorities (UK, Australia, Eurocontrol, Central America, etc.), directly from airlines, satellite avionics providers, etc. Live flight tracking is a deceptively difficult problem - on the surface it seems as if you could simply collect data and regurgitate it (that's what I thought before I came onboard), but there is actually an enormous amount of processing and inference based on sometimes incomplete, inaccurate, and conflicting data, even for mainline airline flights. That's not even getting into GA or flights in areas of the globe where we lack complete coverage. It's a really interesting set of problems!