Quoted from TFraelich:Mr. Bell,
As most people that have ever watched a movie on Blu-Ray or DVD know who have seen the warning at the beginning of the movie, the unauthorized sale of goods which violate the trademarks and copyrights of others can subject not only the seller to legal jeopardy, but anyone trading in such goods as well. Thus, you are willfully placing your customers in legal jeopardy by selling them unlicensed products.
Tim Fraelich
Threatening Pinsiders that may buy something from someone that may or may not be infringing on your client is a douche move.