I believe this type of thing would be done to hide a particular flight path. If there were only a few, a conspicuous flight would be more noticeable. Throw a lot more noise at the board and your conspicuous flight becomes invisible.

I believe this type of thing would be done to hide a particular flight path. If there were only a few a conspicuous flight would be more noticeable. Throw a lot more noise at the board, and your conspicuous flight becomes invisible.