<i>You risk inconveniencing people who are assigned just a few addresses because you potentially end up blocking many of them due to the actions of a few on the same subnet, but you can&#x27;t be held responsible for hosts&#x2F;ISPs doing IPv6 wrong.</i><p>Not to mention that some ISPs do carrier-grade NAT specifically due to the limitations of IPv4, so blocking a single IP(v4) might affect multiple people as well.