The irony here is pretty rich. You don't do it, although your privacy says you might do it for as long as the account is open. Meanwhile, Google (a) can't do it, and (b) specifically states they won't do it in their privacy policy.
But Google's the one we should be worried about.
I didn't give a crap about the redirector until you started making privacy vis a vis Google DNS an issue on Hacker News.
You have to setup every IP you might make a query from as a "network", do you not? How else would they know you're the one making the DNS query? It's not like a Cookie header is sent via DNS.