Comment Red-shift (Score 1) 129
As light is initially slowed down to make "room" for the invisible event to take place, there is going to be a red-shift in the light because the waves must start arriving more slowly. While this change can be made subtle, that means that an "attacker" needs to either spend a long time slowing down the light, or the "attacker" would only create a small gap in time in which to work.
Still very cool though!