I see a guy camped out taking pictures out in front of your house as a no-win situation. If he's on a/the job, he's not going to tell you anything, which is just going to piss you off. If he's not on a/the job, then he's probably doing something shady, which
should piss you off.
And, as for the guy in the car, he's not going to be happy to have to talk to you because you're either a) screwing with his job or b) screwing with the "job" he's about to pull.
Either way, everyone is pissed off. See, no win
So that's why I just call Tom or Tyr