Several services provide real-time tracking and browsing the position of aircraft in flight. By using the aircraft’s registration number (aka the ‘tail number’, like a vehicle license plate) and the transponder code that reports position to Air Traffic Control, it’s easy to find who/where of aircraft movements. Private flights presently have the option to block the reporting of such data.
The Aircraft Owner’s and Pilot’s Association (AOPA) is presently conducting a survey of whether the federal privacy policy regarding ‘private’ aircraft (as opposed to commercial aircraft) should be amended to remove privacy blocking with some exceptions.
See “FAA proposes limiting blocks on aircraft.”
(http://www.aopa.org/advocacy/articles/2011/110304faa_proposes_limiting_b...)
AOPA describes the poll as:
“Do you favor or oppose a privacy provision that would allow aircraft operators to continue to block their aircraft from tracking? Private aircraft operators have historically been able to elect for privacy reasons to block the reporting of their aircraft's flight activities by commercial organizations that track aircraft movements around the country by registration numbers. The Department of Transportation is now asking for comments on an action that would remove this privacy provision except in cases where there is a ‘verifiable threat to person, property or company, including a threat of death, kidnapping or serious bodily harm’ or ‘a recent history of violent terrorist activity in the geographic area in which the transportation is provided.’”
In a sense this isn’t too much different than data conveyed by car movements with toll-tags.