A side point here..
I have actually seen someone back-feed the electrical service and here's what happened: Nothing.
When he tried to power the entire neighborhood from the feed for his house, the 7.5KV genny just labored down. There's no way it can power all the street lights, and other homes in the area let alone get through the xfmr on the pole.
I'm NOT saying there isn't a danger to utility workers, there certainly would be under the right circumstances.
But if someone tries to back feed the first thing they'll probably run into is loading problems.