[tialaramex]

Note that in any configuration where you end up asking remote DNS servers about some particular name the operator might well be selling the list of names queried and their answers, this is called "passive DNS" and is aggregated then sold on so it isn't PII by the time it's sold (purchasers can't tell who asked, only what was asked and what the answer was)

Where people set wildcard DNS this means passive DNS reveals typos, as well as such "hidden" services. wwww.example.com and ddd.example.com are common typos for www for example whereas int-test.example.com is maybe interesting to black hats.