From May 2010.

"The new .xxx top-level domain is causing brand managers and trademark owners anxiety. Thankfully, a "defensive registration" process is in place that allows registered trademark owners to block their marks from being abusively registered as a .xxx domain by a third party. Defensive registration can prevent unwanted affiliation between a wholesome brand and the adult entertainment industry. On March 18, the Internet Corporation for Assigned Names and Numbers (ICANN) approved the formation of a new .xxx top level domain for the adult entertainment industry and has asked ICM Registry to operate the domain. An .xxx top level domain was first proposed by the adult entertainment industry in 2000 and, after 11 years of hearings and three earlier refusals, ICANN finally approved the domain." --AdAge. Ad from November 2011.