[Terr_]

I think it's a bit like radar and sonar.

Receiving bounced waves gives you information, while emitting it gives out information, and may make you a target. A streetlight is a neutral-emitter that doesn't usually need to worry about being attacked, unlike a bobbing flashlight held by someone walking in the dark woods.

A difference with car-headlights is that the car itself is a protective shell, and it's hard for other cars to hide in bushes.

[giantg2]

Street lights still have shadows and areas that they don't cover. You still have things like the opposite side of cars that you can't see even if you have a street light (ie your bushes example applies with or without street lights). When I say to carry a light, I don't mean the light on your phone, but a proper means of illumination. If done correctly, this would provide plenty of information before in attack range (assuming you're not getting shot at long range, which isn't really an issue in common crime today). There are also defensive tactics with the lights that can benefit you. For example, if someone is waiting in the dark for you (as your comment implies) and you blast them with 1200+ lumens maybe even in strobe mode, you now have the advantage, streetlight or not.

So yeah, you can give out some information by holding a light, mostly about position. You give out much more information being in the light from street lights, such as sex, age, weakness/disability, etc that are more useful to criminals.

The are plenty of areas without street lights or with minimal street lights today. The primary issue as it pertains to crime is not a lack of street lights, but other factors such as socioeconomic factors and defensive knowledge.