Few things can strike fear into the heart of the IT department like an attack on a company’s Domain Name System servers. That may explain why companies are spending so much time to deploy myriad, complex security measures to keep their DNS protected from malicious attackers.
http://www.networkworld.com/news/2007/071807-it-losing-battle-against-dns-attacks.html
http://computerworld.com/action/article.do?command=viewArticleBasic&articleId=9027345