Dear [name of infringer]
It has come to my attention that you have made an unauthorized use of my copyrighted work entitled [name of work] (the "Work") in the preparation of a work derived therefrom. I have reserved all rights in the Work, which was first published in 1999 on http://www.mycompany.com, and I have registered the copyright.
Your work entitled [name of infringing work] and which appears on your web site at http://www.yourinfringing.com, is essentially identical to the Work and clearly used the Work as its basis. [Give few examples that illustrate direct copying and/or unfair use.]
You neither asked for nor received permission to use the Work as the basis for [name of infringing work] nor to make or distribute copies of it. Therefore, I believe you have willfully infringed my rights under 17 USC §101, et seq. and could be liable for statutory damages as high as $100,000.
I demand that you immediately cease the use and distribution of all infringing works derived from the Work, and all copies of it, and that you deliver to me all unused, undistributed copies of it, or destroy such copies immediately, and that you desist from this or any other infringement of my rights in the future. If I have not received an affirmative response from you by [date] indicating that you have fully complied with these requirements, I shall consider taking the full legal remedies available to rectify this situation.