Nevertheless, people do stupid things.

Here it is extremely difficult to steal electricity from one detached house and bring it to another. If you have attached houses, that would depend on the location of the electrical mains as well as meters. If each has those separate from the other, it is again difficult.

Ostensibly, the electric utility is running computer models on how much each customer should be using. If Customer #1 is using x KWH and next door neighbor is using 25% of that, hopefully someone notices.

Anyway, all this goes out the window when your power is supplied by a generator in your yard.