I'm surprised that anyone would even think of suing users who use your instrument over the copyrights of its built in sounds! There must be some kind of implicit right of a performer to use the sounds produced by an instrument, although "sample" or pattern based instruments do tend to blur the line a little. Certainly, one must draw the line somewhere, cf.: https://en.wikipedia.org/wiki/Timbaland_plagiarism_controver... However the case in TFA seems pretty cut and dry to me, or am I mistaken?