And also the easiest to see whether they've been tampered with or tapped into.
A few years ago some enterprising people decided it would be a good idea to grow pot in an abandoned factory nearby. The growers routed conductors around the meter and got free electricity to run their grow house for a number of years.
No one noticed, ot maybe no one wanted to notice, until the building caught on fire. I don't recall the growers were ever caught though. probably had some pretty good political cover.