We also see this with extranet/supply-chain-type connectivity between large companies who have overlapping address space, and I'm afraid it's only going to become more common as more of these types of relationships are established.
Fortunately, IP addresses are not intended for use on the Internet. Rather, they are intended for use with Internet Protocol (IP) implementations. That's why the RIRs, in alignment with RFC 2050, section 3(a), do give out IP address allocations to organizations who are connected to extranet-type networks. If you read RFC 1918, section 2, category 3, you will see that this is consistent. So if the power companies want to assign a unique network address to all power meters then there is no good reason to stop them. After all, it is consistent with the goals of the original IP designers to address every light switch and toaster. Just remember, IP addresses are *NOT* Internet addresses. They are Internet Protocol addresses. Connection to the Internet and public announcement of prefixes are totally irrelevant. --Michael Dillon