Novelists Inc. (a nonprofit representing novelists) is pushing for legislation to require used-book sellers to pay a percentage of sales to publishers and authors for any book re-sold within two years of its original publishing date. You can read some discussion about it here.

To me, a law like that sounds like it would lead to more books being thrown away and pulped. Used books are a great way to keep people reading, which helps the industry as a whole.
I can understand that used-book sales don’t count toward an author’s sales numbers and that it must be maddening to see a “Buy This Used for $4″ link on Amazon right alongside the full-price new version of your book. It’s important that people buy your book. But isn’t it important that people read it? (And maybe buy your next book in hardcover because they just can’t wait)
-Marcia