Having a couple chained together muddies the results enough that unless you're accessing things that you're REALLY not supposed to won't bother to track back. DNS is a 'ask the next guy' type of ordeal with some along the way caching the responses they've received for whatevr length of time the TTL is set on a record. Technically you could set a DNS server to cache things infefinatly and never querry a public server again past the first call but it would quickly be full of outdated records that point you to the wrong destination.