Unfortunately, lots of companies jumped into the 'smart grid' without being very smart, and the first time I heard of 'proprietary' smart grid meter systems, I knew that the predictable result would be insiders in the electric company training others on how to alter the meters to steal electricity. What will happen next is the industry will respond claiming encryption will solve the problem. All this will do is ensure there is a steady growth market for smart meters with new encryption every year. Either organized crime will pay off (or threaten to break the kneecaps) of an intern at the smart meter vendor, and they'll have the new keys, or a vendor executive will leak the keys to the same criminals so the crooks can profit, and then the vendor can profit some more replacing all the meters.
If you want to stop the insanity, please contact me for my contracting rates for modifying the POErduino and Open Silicon open-source hardware for a smart meter application.