Comment by toast0
If you control the IP or domain via a BGP hack, you can get a certificate issued while you control it, as long as you control it from the perspective of their CA.
You've got to be pretty lucky, or do a lot of IP cycling for your vector to be terribly useful. A paranoid user of IP certs would let their new public facing assignments settle for a week before using them; but I suspect few people will start using IP address certs, because of usability.
I wouldn't write off the use of IP certs just yet.
AFAIK IP address certs would provide a way to create a secure browsing context in your browser, which is required for service worker ('offline' background threads) and some File API, which could open up a new class of programs that host for friends and family.