Lunixer (and others): Go back to my post on the (sigh) first page of this thread:
here. On reviewing it, I see that I failed to mention that giving away or selling the original purchased copy of that legitimately acquired work falls in the same category as "sharing with 50,000 of your closest friends." The only difference that I can see is that you've violated copyright by creating one extra copy (or thereabouts) rather than N extra copies (one per download, with potentially large N). The extra copy (or copies) in this case are the one(s) you kept when you sold, donated, or otherwise transferred ownership of the original book (or eBook, or CD, or DVD, or whatever).
The penalties in US copyright law are quite different for small numbers of copies than for large numbers. I don't remember what the specified difference is, but I'm pretty sure that "one copy" would fall in the small number case. As a practical matter, you're quite unlikely to be prosecuted for copyright violations of this kind. But it's still quite clear that it's a violation. If, on the other hand, you'd dumped the original CDs (or eBooks, or DVDs or whatever) in a box in your attic/garage/storage unit/whatever you'd have been squeaky-clean legal.
Xenophon
(who is not a lawyer, and is not giving legal advice. If you need legal advice on which you can place reliance, go get a real lawyer!)