I put that pdf on a website. It's probably the most insanely useful thing in all of existance. I tell only my group.
And now things get tricky. Take any of the above examples regarding the pdf or pdfs and add "Other people find out about it and download it as well."
Am I a nasty, dirty pirate?
Yes.
As a small publisher, I too recently found my work on scribd. To be frank, I don't mind our customers sharing our products around the game table (preferably in a printed format), but when someone puts it on the net for free - that takes potential money right out of our pocket.
As a small publisher, a good selling .pdf sale for us is 150-250 copies in the first month or so, but I was disgusted to find that nearly 1,300 people either viewed or downloaded the product for free (more than any one individual product sale in our 5 years of publishing).
It is like going to work, working hard that day, and your boss telling you you're not getting paid. Unlike a WotC employee, I do not get paid until I sell my product. And if they don't sell products, they fire employees.
If people LOVE our products so much, then please tell your friends to invest in our company by paying the $4.00-$7.00 dollars to encourage us to make more of the same and to continue to do what we do.
If I lived in a society that I didn't have to pay for food or a car payment, house, etc. I wouldn't mind people downloading our products for free, but since people who buy our products need money for other things, so do we.
I mainly got into publishing for love of the game, but I do personally invest my time, work, and money in each of our products (I also sometimes get burned out).
What I think is really disparaging about the whole thing is WotC even reduced the costs of their .pdfs with the launch of 4th Edition instead of pricing them, as they did before, as the same cost as a printed book. It is just a slap in the face.
As for the minor argument, I was a minor too - before file sharing and the internet - I saved my hard earned money (working at Dairy Queen, allowance, odd jobs, etc.) to get the D&D books I loved. It is called learning responsibility and managing your priorities. After all, I did not get all the books I wanted.
More importantly, I did share with friends (either their books or mine), and did borrow from the library D&D books I fortunately found there, but in the end - I had to give them back. And if I lost a book or did not return it (either to the library or my friend), I had to pay a fee or buy the book. That is something that you can't do with a file share - return it.
If you love a .pdf and want to share it - print it out and keep it around the table like any other book or better yet, buy a copy for a friend (if you can afford it). There is no excuse for illegal file sharing.