well...imho, they should be delegated to localhost. and everyone should have a localhost zone with the proper address in it, to go with their 127.in-addr.arpa zone file.
but then again, some people think i'm weird.
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Well, in that context all of RFC 1918 space should never have been delegated and private networks built out of 127.0.0.0/8. In the mists of time, I actually built a network that way. Seems that the prevaling wisdom was to delegate whole other blocks for tom-foolery. Given the lax registration checking, it was considered prudent to actually have real servers host these zones so the possiblity of "hijacking" would be reduced. There was a recent attempt to actually have the servers provide an authoritative response when a query was received. This engendered a significant raft of unexpected responses. Apparently several fortune 1000 companies have used this space for network mgmt. and propogate the prefixes in the Internet. This will be much to their dismay when authoritative replies are once more available. YMMV.