I stumbled across a comprehensive collection of O'Reilly CD books on a web site today, and I fired off a quick email to email@example.com. The way I see it, I benefit from those books, as do the writers, many of whom are also Monks, and it bothers me to see that benefit siphoned off by freeloaders.
I received an email in reply in about two hours, which I will share:
Thanks for taking the time to report suspected copyright infringement to us. We will investigate and take appropriate measures to prevent further misuse of our materials. We (and our authors) are truly grateful for the support of readers like you and we look forward to continuing to provide you with top-quality technology publications.
So, whatever your take on the issue, I think that O'Reilly is both aware of and responsive to the issue.