Amateur astronomers considered a threat in NATO paper
NATO communication.....point 30:
III. POSSIBLE THREATS TO SPACE-BASED ASSETS:
30. The availability of tracking data by amateur satellite observers from all over the world, who post their findings on the Internet, facilitates the tracking and identifying of satellites in low orbit. The increased sophistication of technologies such as radar, optical telescopes and passive radio frequency receivers makes it easier to track satellites in LEO.