http://www.iab.org/documents/docs/2003-09-20-dns-wildcards.html "There are many architectural assumptions regarding DNS behavior that are not specified in the IETF standards documents describing DNS, but which are deeply embedded in the behavior of Internet protocols and applications. These assumptions are inherent parts of the network architecture of which the DNS is one component. It has long been known that it is possible to use DNS wildcards in ways that violate these assumptions. Recent deployments of DNS wildcards with A records at high levels in the DNS tree have shown by experience that the cost of violating these assumptions is significant. ..." -- Thomas Roessler <roessler@does-not-exist.org> At-Large Advisory Committee: http://alac.info/