This is one of the benchmarks of cluelessness. The other is that the addresses don't have reverse DNS.

Perhaps they do resolve interally to BT, it's just that your resolver can't get anything useful via the normal channels: danny@sofos% dig @a.root-servers.net 16.172.in-addr.arpa ns ; <<>> DiG 8.2 <<>> @a.root-servers.net 16.172.in-addr.arpa ns ; (1 server found) ;; res options: init recurs defnam dnsrch ;; got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 6 ;; flags: qr rd; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0 ;; QUERY SECTION: ;; 16.172.in-addr.arpa, type = NS, class = IN ;; ANSWER SECTION: 16.172.in-addr.arpa. 6D IN NS BLACKHOLE.ISI.EDU. 16.172.in-addr.arpa. 6D IN NS BLACKHOLE.EP.NET. ;; Total query time: 108 msec ;; FROM: sofos.tcb.net to SERVER: a.root-servers.net 198.41.0.4 ;; WHEN: Fri Dec 29 11:42:12 2000 ;; MSG SIZE sent: 37 rcvd: 98 Though I agree that using reserved address space in this manner is [usually] a bad idea, I think we [NANOG] have been through this dicussion more than a few times in this past. -danny