The thing is though it might not be “the secret of the universe”, it
is not theirs to sell, and that is theft. End of story.
So now what to do about it? I think contacting the AG of your state
is a good first step, over here in Australia a good first step would
be to contact the federal police, I have done this once before quite
some years ago now. Was it worth the agro and hassles? At the time
no, now yes.
Might seem a bit of a weird answer, but I was at uni back then at it
took quite a bit of time (not to mention money!) out of my studies to
do this, and it wasn’t over anything that would have made me or the
infringer much money in the long run. However when I look back now, I
do so with the understanding (and knowledge) that you can get
recourse and that your ideas are worth protecting, and the law agrees
with these sentiments.
So now it’s up to you as to how strongly you feel about this theft,
and remember if they think this item is worth copying (stealing) then
it must be of some real value and I would think it should be worthy
of your protection…