Blue Jeans Cable took much the same approach to Monster Cable. The response was an all-time classic. I've posted snippets here before but can't resist doing it again:

   if you file on this sort of basis, you are in
   Rule 11 frivolous-claim territory
   ...
   You are required, as a matter of legal ethics,
   to display good faith and professional candor
   in your dealings with adverse parties, and you
   have fallen miserably short of your ethical
   responsibilities
   ...
   Read the patents narrowly, and Monster loses;
   read them broadly, and Monster loses.
   ...
   I spent nineteen years in litigation practice
   ...
   I am "uncompromising" in the most literal sense
   of the word. If Monster Cable proceeds with
   litigation against me I will pursue the same
   merits-driven approach: I do not compromise with
   bullies and I would rather spend fifty thousand
   dollars on defense than give you a dollar of
   unmerited settlement funds.
   ...
   Not only am I unintimidated by litigation;
   I sometimes rather miss it.