In Florida v. Riley, from the US Supreme court, it was ruled that police did not need a warrant to hover over someone's house with a helicopter to peer into the roof of a greenhouse to check for marijuana.
There's a lot that maybe we shouldn't do but is completely legal anyway.
Something being in plain sight is not a sufficient condition for legally photographing it. You cannot, for example, point a camera into your neighbor's bedroom, photograph the results, and distribute it on the internet, even if, say, the camera was on public sidewalks.
Yeah, it's possible to predict a poor outcome from something like this. It's possible to predict a poor outcome from anything. It all depends on how much fear you want to live with.