Yesterday I sent out a link to my Kickstarter backers to the digitial version of the book I published. The book is in PDF format. It’s “open”, no DRM protection, nothing.
I used bitly to track clicks and I watched them trickle in slowly (as expected) until around 2pm when—in a 15-minute time span—this happened:

Of the 192 total backers to my project, 106 received this link to the book. It’s possible there was a flurry of genuine activity for 15 minutes, but it looks shady. There’s no proof of referral traffic (the link wasn’t posted on another website), but it’s intriguing.
I’m not getting bent out of shape about this. If people are sharing the link, they’re sharing the link. There’s nothing I can do about it.
I myself have torrented movies, music and books from time to time, so I have to put my money where my mouth is and let it happen, if it’s going to happen.