Wayne,
There is loads of discussion about this, particularly on the Kinetic SBS-1 forum where the subject has been done to death!
When the first Mode S receiver appeared around 2 years ago, there was a newspaper "scare story" that said all Mode S receivers should be banned, unless used for "official" purposes. Kinetic failed to produce their version of Network data, even though this was promised when their box was first produced. When AirNav rolled out their 5 minute delayed Network system, more "scare stories" were put out (mostly by Kinetic) which said that the AirNav network wasn't legal and that it would soon be shut down by "official agencies" - although it was never actually said just who this was supposed to be!
It has long been accepted internationally, that 5 minute delayed aircraft data does not represent any security threat and there are a number of different providers which supply such delayed data. This is the way it is I'm afraid, and it's unlikely to change. Don't try applying logic to the argument about live data received by individuals and 5 minute delayed network data - you will just get frustrated :-0
See the link below regarding the newspaper article:
http://www.kinetic-avionics.co.uk/forums/viewtopic.php?t=2252&highlight=newspaper
