The moment I learned what this was about, right away my instincts tell me it's just waiting for something bad to happen.
If not for people driving while looking for (nothing), then people waiting at pokestops (or whatever) to rob people. Or like the one guy that was streaming and happen to see someone being murdered.
ETA: Well, the last thing I mentioned, completely unrelated to the app, I'm sure. But (if true) how do we know the person that was allegedly killed wasn't on his way somewhere (or even THERE) looking for a pokemon, and whoever was waiting there for someone?