This is an amusing thread.

And this is a huge post. If you don't care about intellectual property law, skip it. But if you do continue reading, be aware that I'm not trying to be accurate in general, only as it applies to this thread.
First, if anyone reading this is a lawyer and wants to clarify, please do; IANAL, but I've read a lot about IP and I think I grasp most of it, although probably not the detailed nuances. Here are the categories I see:
1. Trademarks. If someone uses a trademark and gives credit to the owner, there is no infringement. This is why you'll see all kinds of advertising that mentions the trademark ownership of competing products. There are exceptions to this; it's based on dilution of product identity. And no, that's not exactly the same as WotC with their beholders or yuan-ti.
2. Patents. A patent is exclusive authority to produce, or to control production of, a system, technique, process, method, ... A patent is used to protect a method of accomplishing something. They are relatively short-lived (17 or more years, depending on the type of patent; used to be flat 17 years, but that's changed).
3. Copyrights. They protect the
expression of an idea,
NOT the idea itself. So, if I publish an item from the previous category (patents), I can copyright that publication, but not the system, technique, process, etc. Because only the expression is protected, there are gray areas. For example, the WotC XP table would be protected: font, type size, column layout, etc. Any reasonable judge would extrapolate and rule that changing only those items would still constitute a violation. However, a formula that generates the same table of numbers may or may not be a violation. A formula can only be covered by a patent, and WotC doesn't have a patent on their
game system (note the use of the word "system").
4. Trade secrets. These can be anything that would normally fall under #2 or #3, but the creator considers keeping them secret to be more beneficial in the market than releasing the information. For example, instead of filing a patent and trying to enforce it, it might be easier to keep it secret. There's a long discussion about whether that's practical or not. But this thread isn't about trade secrets, so I'm not going into it.
It's very important that #2 and #3 be clear: you cannot "copyright" a way to do something, and you cannot "patent" a book.
Fair use in the U.S. is based on the idea that writers and journalists will want to be able to quote other written works. This is the whole "standing on the shoulders of giants" philosophy. So the "fair use doctrine" was established to allow such things. However, the framers of the Constitution couldn't envision the electronic world we live in and Congress (opposite of "Progress"?) dreamed up their own definitions. That's one of the reasons we have such a mess on our hands: our congressmen react to lobbyists, not to technical experts who represent the views of the citizens.
Having said all that, scanning a book and distributing a PDF is illegal. (However, it is not "theft", or "stealing", or "piracy". It is "copyright infringement". Those first three terms all have specific meanings and anyone who uses them to refer to illegal distribution of intellectual property doesn't understand the proper use of the words. IMHO, of course.

) It was not, at the time our country's laws were written, feasible to photocopy a book or scan an entire document. They weren't concerned about such things; they were concerned that a writer wouldn't quote large sections of text. This is why the law doesn't say how much can be copied and still be within the "fair use" statute. Note that copying something
for your own use is still illegal! The courts, if you were prosecuted, would consider many details, including but not limited to, profit motive, amount copied, and breadth of distribution.
All of the above leaves out one key point: laws are made for the protection of citizens. One of the biggest mistakes (again, IMHO) this country ever made was to grant corporations the legal status of an individual. This significantly murkied the water in a number of ways, and was
NOT the way the Constitution had originally been conceived.
Because laws are made to guide citizens in ethical conduct (what are laws except an implementation of morality and ethics by a group of people known as "government"?), they can and do change. To argue that some particular act is illegal and the perpetrator is a criminal is false. Someone who commits an illegal act is a suspect and is
alleged to have committed a crime, but they are not a criminal until convicted. But laws change because of court decisions -- look at how the pendulum is swinging in
Roe vs. Wade right now.
We even have a phrase to represent the kind of activity that invites prosecution: civil disobedience. This is when a citizen purposefully disobeys a law and incurs the wrath of the government, or other body, in order to point out how the law is flawed. For example, see this link
http://www.papersplease.org/gilmore/ if you'd like to read about John Gilmore, an individual who decided that he wanted to travel to Washington, DC, to visit his congressman, but refused to show identification to board the airplane leaving San Francisco. He wasn't allowed to board. His constitutional right to meet with his legislative representative was infringed, as well as his guarantee against illegal search and seizure. In addition, he was arrested for breaking a law that the Transportation Security Administration refused to reveal to him ("You broke a law, but we can't tell you what it is -- national security"!). It has been said that the first thing a tyrant does is institute policies "for the safety of the population". Keep your eye on New Orleans -- it'll be interesting to see if people are
forced to evacuate and how the government handles those that refuse.
Another example is Philip Zimmerman, author of the PGP encryption software. The government claimed his software was a "munition" (technically, encryption devices are munitions, and export to a non-allied country is considered treason). So they forced him to shut down his web site where the code resided. His solution? He wrote a book and asked the government for clearance to export it. The executive branch gave him the thumbs-up. The contents of the book? The complete source code to the software! The book was even printed without page numbers or headers/footers, specifically so that it could be easily scanned and OCR'd. Once the Justice Department learned of it, they eventually dropped the case. But only AFTER Phil had spent hundreds of thousands of his own dollars to defend himself! (I bought a copy of said book, but can't find it on my shelf right now -- I probably tossed it out when I moved a couple years ago.)
All of that shows that individuals can, and SHOULD, push the limits of the law. And while it's not a valid argument to say, "everyone else is doing it, so I can too!", it is also true that if everyone else
IS doing it, the law is likely to change.
To sum up: is it illegal to scan a book into a PDF, even for your own use? Yes. Is it illegal to scan a single page (or two) from a book for your own use? Probably not. (But you can be sued for anything, and usually the money wins. No, it's not fair, but our laws are not designed to be fair -- and don't let anyone convince you otherwise.) Is it illegal to discuss with someone else the content of the book? No. Is it illegal to give a list of chapter titles to someone else? Probably not. Is it illegal to read the entire book out loud and have your friend listen to it on the other end of the phone? Probably not. Is it illegal for said friend to record the book while you speak it? Yes.
As I mentioned earlier, IANAL. And if you use this text as legal advice, you're an idiot.

My effort to instruct was probably in vain; I've found most people don't take an interest in their own welfare. Heck, why else would voter turnout be so low in this country? (But I'll bet the voters turn out in droves in 2008, eh?!)
If I've made a fool of myself with this post, please tell the world about it and post a correction. :\ I for one would really like to know if I have this wrong...