You will often find recommendations on the Internet to use openly available DNS servers such as Google DNS $(8\mathrm{.}8\mathrm{.}8\mathrm{.}8,8\mathrm{.}8\mathrm{.}4\mathrm{.}4)$ or OpenDNS instead of your local ISP's DNS servers. This is because these servers are typically able to resolve queries much faster than your local ISP DNS servers. Can you explain why using such openly available DNS servers may actually lead to poor download speeds and increased latency, e$.$g$.$ when downloading a large movie from iTunes $($as compared to using your local ISP's DNS servers$)?$