I dont know for sure, but to go to the extreme of sending out things to check the heat and stuff I would think they would have to have some good reasons to. If people dont know and stuff I doubt they would unless they suspected you of growing. Maybe if you had a large grow room and somebody knew and got busted and were a rat and told the cops they might check out, but other than extremes like that I honestly doubt you are in trouble if you just dont let the world know about it. A personal grow room I definately doubt the cops would bother you ever if you never told anyone, even if they used heat reading stuff.