Without getting into the moral dilemma of the situation, the first thing that came to my mind was, would it even work? It just doesn't seem feasible that a flashlight drop in would be powerful enough to trigger the stoplight sensors, and that's after assuming you would even be able to get the modulation right.

My second thought is, what's the use? If the situation was that bad where you feel justified in using it, why bother messing around with electronic gizmos? Just run the red light. If you're not worried about the legality of possesing one of these items, why would you be worried about the legality of traffic laws?

But in reality, if there there was every a time where you'd need one of these, people won't even care about the traffic lights. So it wouldn't matter if you had the power to change the lights to green or red yellow or whatever, the instersection is going to be blocked. The right of way means nothing if there's a car in front of you with no place to go. In an emergency situation even the fire department and police have trouble getting through, so I doubt this toy would really have any effect.