So if I have a yard sale and sell some of my old books, the Association of American Publishers will consider me a “criminal”? Nice.
The ruling went in your favor. You can sell your books.
No, you could always do that under the "first sale" doctrine (a copyright holder gets to collect its royalty only the first time the copyrighted thing gets sold). No one ever disputed that so long as you bought your books in the U.S.
The issue in this case came about because textbooks are subsidized and/or price controlled in some foreign countries, so it created an arbitrage opportunity for people who could buy books overseas and re-sell them in the U.S. The specific issue before the Court yesterday was whether the "first sale" of a copyrighted item means only the first sale in the U.S.; the Court ruled (6-3) that a first sale anywhere counts.