Well... there are some articles about ebook piracy but most of the figures are really off, like :
More or less like the ones of movies/mp3s. Very hard to quantify because not all of book sales are of mainstream novels like with movies but there are also technical books (I still have to see a technical movie =P) and the statistics of those do not exist.
I am a collector. I have around 20k books most of it science books and some art and just around 200 fiction. I really like to go and pick one at random and read something from art or some other science book for a short while. I started my collection mostly because I couldn't afford the books at the time and there weren't any online (no kindle/amazon at the time). And I further enriched it when I was confronted with 5 massive boxes of books during moving. Now I would only buy a book if it's an antique. Also I wouldn't buy a DRMed/geographically locked book if possible.
If you think I don't have any moral fiber left you may be right. In reality I've worked very hard to get rid of that quality for years and am quite proud of the results. On the other hand you may find that I have a different "set of moral values" where killing and so on are bad but downloading digital media from the internet is not really in the baby-killing category.
Furthermore, I really consider that copyrights for science and reference books shouldn't be handled as the fiction because this just limits the progress of every country. What I perceive is that usually the people that take the moral high ground are the people with means to buy while the people scorned are the poor that cannot buy things. While in the realm of physical things this is certainly valid it loses a lot of weight when we go to digital media. Would that poor student buy that $400 reference book? Or that doctor from a third world country? Certainly not. Was the "illegal" download from I-kil-babies-for-fun.com worth? most probably! On the other side, for fiction books like from Stephen King, J.K. Rowling I fully support the legal copyrights because a) they directly earn their daily bread from it and b) it's just for leisure that you read those books... it's a luxury.
On the other hand... apparently ebook piracy is not that bad for book sales:
http://www.bnet.com/blog/publishing-...publishing/417