First off, understand that you can only pirate ebooks. Real books still have to be shoplifted, which, for whatever reasons, isn't called piracy, but shoplifting. Probably it's the lack of cool hats, parrots, and eye patches among the shoplifting community. Posers. Anyway, most, if not all, book pirates are people who use eReaders.
As of 2011, ebooks account for roughly 10% of all the books (not including text books) being sold.
Within that 10%, Amazon.com represents 70-80% of the ebook market. I'm guessing it's closer to 70 than 80, since Apple claims to have 22% tied up with its iBook store. That leaves 8% unaccounted for. But let's be generous and assume that a whole 10% of the ebook market is divided between Smashwords, Sony's Reader Store, Barnes and Noble's Nookstore, Kobo, and the Borders ebookstore, which is separate from, but powered by the Kobo system.
At best then, any discussion of Borders vs. book piracy is only really applicable to one-fifth of 10% of the 10% of all books being sold anywhere, which ebooks represent. That's one fifth of one percent of all book sales, for those of you getting lost in the math. That means for every 500 books Borders sold, they could have sold 501. If only it weren't for those darn pirates. Even homeless people wouldn't notice themselves losing 1 out of every 500 dollars, so I seriously doubt it's enough to put a corporation the size of Borders into Chapter 11.
And remember, this math assumes that a full 100% of all Borders ebook sales are lost to piracy. And that Borders even has that much of the ebook market share, which I also doubt, seeing as the Sony eReaders seem to be most popular after the Kindle and iPad.
It also ignores the fact that book piracy is primarily costing Amazon and Apple money at this point, both entities that actually compete with Borders.
Now let's take a moment to look at the piracy numbers.
Here is the most popular ebook torrent on Earth (in our dimension). It contains 976 books from a wide range of authors, starting with Frank W. Abagnale and ending with Markus Zusak. (Zusak's stolen book, coincidentally, is called The Book Thief.) How popular is this particular bundle of pirate booty? Well, it has 754 seeders, and 208 leechers. That means 754 people, globally, are providing the full file for download, and another 208 denizens of our small blue dot are currently downloading it from them.
That's comparable to, say, the dvd rip of 2010's "Machete". (Which has 759seeders, 189 leechers.) Or the "Wiz Khalifa Discography". (623/214) Or yesterday's episode of InSecurity. (804/370)
Yes, that's right... 1000 ebooks, including the (nearly) complete works of Stephen King, Stephanie Meyer, Douglas Adams, J.K. Rowling, William Shakespeare, William Gibson, J.R.R. Tolkien, Kurt Vonnegut, Dean Koontz, Stieg Larrson, and many, many others... combined, are currently generating as much pirate traffic as a single (essentially unwatchable) B movie from last December. And some remix bundle from a DJ none of us have ever heard of. And a TV show most of us would have to google if we cared.
If that's the kind of math that hammers nails into the coffins of national chains, every business everywhere is in dire and immediate danger. It can only be a matter of weeks before we're plunged into a hellish Mad Max-ian dystopia, where we'll be forced to wear the pelts of feral cats and hunt radioactive pigeons for sustenance. I sure hope you can mutant-proof a soap box...
I guess if you're really intent on nailing yourself to the cause, you can take the Borders downfall as a moment to decry the evils of book piracy. I can't stop you. Neither can these numbers. But you'll be lying. To everyone that hears you, and, worse, to yourself.
Perhaps most importantly, that misguided rally won't help books, or the people who write them, or sell them, just as rants about the dangers of marijauna only make people less likely to heed later warnings about harder, more dangerous drugs they really should avoid at all costs. Misinformation has a price, and that price is trust. In 5 or 10 years, book piracy really could be a problem for the industry. It might help, at that point, to still have some credibility laying around.