Doesn't "public land" in Nevada usually belong to the government? The highway department and highway patrol set up traffic detection sensors (those rubber hose things) on public roads all the time, never mind hidden electronic speed traps, and nobody seems to have much to say about it. I suspect that if I started screwing with the highway department's sensors, I would find some cops at my door at some point too.

I would bet that the law permits these sensors to be planted. If they are on public roads, they violate nobody's privacy as such.

Now, if somebody found some sensors on their private driveway, that might be another kettle of fish.