> Yes, it can screw up caches and return unexpected content. Then the cache is broken. Obviously not getting a response is going to confuse things, but there i

> Yes, it can screw up caches and return unexpected content. Then the cache is broken. Obviously not getting a response is going to confuse things, but there is a way to send back REFUSED without giving a positive or negative answer. Take HN's authoritative DNS server and ask it for information on yahoo.com. $ dig @sue.ns.cloudflare.com. yahoo.com. ... ;; ->>HEADER<<- opcode: QUERY, status: REFUSED, id: 28595 ... They are perfectly right to refuse service to non-customers, but I think it's bad network practice (legally right or not) to return incorrect information.