I would agree with this if the issue were movies or games, but most people know that you can Google "[book title] pdf" and get a free copy. The small file sizes

I would agree with this if the issue were movies or games, but most people know that you can Google "[book title] pdf" and get a free copy. The small file sizes mean that piracy sites don't need to rely on torrents and can just offer a direct download. I frequently see piracy sites in search results just from searching the title of a book. The barrier to pirating a book is extremely low.