He was a member here; I corresponded with him.
Besides the AR with M-16 parts that somehow went full auto, he also appeared to be making unregistered lowers for his friends. His claim was that he only transferred 80% lowers and never, ever, cross my heart, helped anyone do the work. Based on the plea deal he said the Feds offered him, I didn't (and don't) believe him.
Way more detail available on arfcom, where there was an epic thread, complete with copies of warrants and indictments.
"To spit on your hands and lower the pike; to stand fast over the body of Leonidas the King; to be rear guard at Kunu-Ri; to stand and be still to the Birkenhead Drill; these are not rational acts. They are often merely necessary." Pournelle