distribute at 4160 or 16kv and this wouldn't be a problem for long
The direct buried primary line would be unusable to the power thieves, unless they had their own transformer, and the knowledge and tools to tap into the primary feed...Highly Unlikely!
Or 440 AC triple phased. Lets see who lands on their ass.
Wrong, these devices tap the lines by transformer action, at a different voltage, they need a different (in this case smaller) number of turns. I have even heard of people putting these sapping transformers in bird houses and raising them near the power line. They don't need to be touching. Oh, and changing the voltage on the line requires re-engineering of every transformer the utility provides and they should look at the size of the insulators on every pole, very expensive.