What I'm wary about is indeed query logging and profiling, but whether it's one provider or a dozen providers isn't that relevant to me. I make a small effort in trying to gauge which providers are honest and which ones are not.
>"As someone who runs a public DNS resolver, I can tell you that it isn't that hard to build user profiles."
Yes, I understand this. May I ask why you/RethinkDNS are doing this with your users' query data?