Let me disagree with everybody for a sec...
I was glad my books were pirated on the trove (although I was mildly annoyed that they were added to the wrong folder).
First, it means more people get to know them. I believe at least a few would purchase my products if they care to read it.
If they don't even read, why should I care I was pirated?
Also, if they don't have one or two dollars (or ten dollars at most) to buy my stuff... Hey, I hope they enjoy it, and I hope one day they can get enough disposable income to support me or other "indie" publishers.
If they don't, I'm glad I ws able to provide some fun.
BTW, if you have a blog etc. with some followers and want a free copy of any of my books for reviews let me know. As an amateur writer, my greatest enemy is not piracy but obscurity.
(nowadays, I don't pirate RPG stuff because I can buy almost everything I want on DTRPG. If something is too expensive I don't buy it. I have more PDFs than I'll ever read, let alone play. My friends, however, will occasionally pirate stuff, but unlike me they prefer physical copies and end up buying physical books if they really like the PDF).
I think it is only fitting that it was taken down by someone whose job is "largely inspired" by Warhammer (BTW GW will allegedly sue you for using the term "space marine"). My copy is homage, your copy is a crime!
EDIT: I don't discuss politics here but saying someone is "socialist" for attacking intelectual "property" is silly, since many libertarians and ancaps are against this on principle. You do not have the be socialist to see there is something wrong with Disney lobbying to protect a mouse for 120 years after the creator has passed away, after using cinderella, sleeping beauty and everything else in the public domain. In fact IIRC trump was the one who avoided the TIPP that would create even more draconian IP laws with the help of China (while Hillary as in favor). Not to mention: free speech, HPL, REH, the coautl and the displacer beast, sending you to prison for downloading a song, etc etc etc.