Active illumination isn't always safe. Russians in Ukraine have (or at least at one point had) a conundrum where if they turn on the radar to detect incoming HI

Active illumination isn't always safe. Russians in Ukraine have (or at least at one point had) a conundrum where if they turn on the radar to detect incoming HIMARS missiles then the radar gets targeted by HARM missiles. In a domestic authoritarian context, an herbal extract salesman could detect when illumination is shone on the house in preparation for a heist.