You walk into your shower and find a spider. You are not an arachnologist. You do, however, know that one of the following options is possible:
The spider is real and harmless. The spider is real and venomous.
Your next-door neighbor, who dislikes your noisy dog, has turned her personal surveillance spider (purchased from “Drones ‘R Us” for $49.95) loose and is monitoring it on her iPhone from her seat at a sports bar downtown. The pictures of you, undressed, are now being relayed on several screens during the break of an NFL game, to the mirth of the entire neighborhood.