Just to point out - I would propose using the ADS-B output from aircraft which has a LOT more information than that retained by third party flight trackers like FR24 and FlightAware etc.
Well,
ADS-B The primary technology that Flightradar24 use to receive flight information is called automatic dependent surveillance-broadcast (ADS-B).
From:
How it works - Flightradar24.com - Live flight tracker!
As you say, ATC might have a lot more data recorded from the ADS-B transmissions. On the other hand, FR24 may indeed log more ADS-B data with more modern equipment than a government ATC site. I was told recently that the FAA still uses Intel 486 computers at some sites.
Also, in some areas I would think sites like FR24 might have better coverage through hobbyist networks with a large number of nodes than ATC with smaller networks of professional equipment. Most of the hobbyist receivers log the 1090ES signal.
Just a thought but should that information be retained by the authorities for use in the official accident investigation?
Rather than be released for use by the media and adhoc forums
Not sure how you can keep transmitted ADS-B data out of the public domain.
ADS-B is transmitted in the clear and may be received, and spoofed, by anyone with the proper equipment. I'm afraid ADS-C has similar problems in its current implementation.
See:
ADS-B Is Insecure and Easily Spoofed, Say Hackers | : Aviation International News
For the many geniuses and rocket scientists who frequent PPRuNe, here is an excellent technical paper on the subject of ADS-B insecurity:
http://arxiv.org/pdf/1307.3664