https://blog.wireshark.org/2010/04/t-mobile-clever-or-insane/ https://blog.wireshark.org/2010/04/t-mobile-clever-or-insane... (amongst others) Basically some

https://blog.wireshark.org/2010/04/t-mobile-clever-or-insane/ https://blog.wireshark.org/2010/04/t-mobile-clever-or-insane... (amongst others) Basically some ISPs are 'reclaiming' unused/unadvertised IP addresses that are used by Gov Agencies (Military and Security Services) to use on their internal networks. Nothing will break (at the moment) because those networks are not accessible from the internet, and also not routed anywhere, despite being allocated.