One concern about the ADS-B OUT is that any persons may buy a 1090 receiver with the appropriate software and receive any information sent by the airplane within its antenna range on its laptop,
Some already do. Here is ADS-B pseudo radar plot of Sweden.
Flygradar LIVE - Se var flygplan befinner sig över Sverige
Note not all aircraft have ADS transmissions, but about 95pc of airliners in Swedish airspace do.