I dunno, I'm under the impression that v4 already sucks, just that the pain is felt on the other end - users who are IP-banned because their ISP does Carrier-grade NAT, cellphone users who randomly cycle through banned IPs as their phone changes addresses, that kind of thing.
For the most devoted trolls, it doesn't. It's possible to "rent" residential IPs. One guy I tracked for about a year would somethings use such IPs. I knew they were him because he was too sloppy to change his behavior and language.