I found this article and got a chuckle out of the response letter it contained to Joseph Perea of Prenda Law.
http://fightcopyrighttrolls.com/2012/06/23/properly-respond-to-a-demand-letter-never-hear-from-blackmailers-again/
http://fightcopyrighttrolls.com/2012/06/23/properly-respond-to-a-demand-letter-never-hear-from-blackmailers-again/