I hate to be a buzz-kill here, but streetlights always have power available to them, and utilize a light sensing switch to turn them on or off.
If you cut into the right wire on a streetlight whose bulb is “off”, (meaning it is not illuminated at the moment...) you stand a very good chance of getting fried.
What you say may be true for suburban and rural areas, bit what I have noticed in the urban areas is that there is a light sensor on one “main” pole that controls a few blocks or so of the lights “down stream”. Where I work I have seen them go on and off simultaneously for several blocks at a time. I guess it saves money on buying light sensors.
Great old lamps.
You're no buzz-kill here. Call it occupational hazard, and if they lose they can file a claim with their insurer. *\;^)
Different streetlights operate different ways. If I understand correctly you are suggesting that someone would have to go up each pole to apply a piece of electrical tape over each eye. I doubt it.