No need for downvoting this comment. The title ends in "What Now?", the OP asks HN if it's legal to post the C&D letter, and no where in the OP's blog does it

No need for downvoting this comment. The title ends in "What Now?", the OP asks HN if it's legal to post the C&D letter, and no where in the OP's blog does it say "Of course I've contacted my lawyer". earle's advice is the best advice posted yet.