Some readers were confused about my comment below that the Consumer Product Safety Improvement Act is having a negative impact on used booksellers. In short, the CPSIA bars the sale of children's books printed before 1985 due to concern that the ink might contain lead. As the Washington Post reported:

Legislation passed by Congress last August in response to fears of lead-tainted toys imported from China went into effect last month. Consumer groups and safety advocates have praised it for its far-reaching protections. But libraries and book resellers such as Goodwill are worried about one small part of the law: a ban on distributing children's books printed before 1985.

According to the Consumer Product Safety Commission, the agency charged with enforcing the act, lead in the books' inks could make its way into the mouths of little kids. Goodwill is calling for a change in the legislation even as it clears its shelves to comply, and libraries are worried they could be the next ones scrubbing their shelves. . . .

Scientists are emphatic that lead, which was common in paints before its use was banned in 1978, poses a threat to the neural development of small children. But they disagree about whether there is enough in the ink in children's books to warrant concern. . . .

The legislation, which passed with strong bipartisan support, was a reaction to lead's being discovered on and in thousands of imported toys, mostly from China, in 2007. It restricts lead content in products designed for children age 12 and younger to 600 parts per million by weight; the threshold drops to 300 parts per million in August of this year. Items as varied as bikes and jewelry are affected.

So are books such as "Madeleine," "Goodnight Moon" and "Corduroy."

Lead was phased out of printer's ink following the 1978 paint ban; lacking a firm date for when it effectively disappeared, the safety commission has ruled that the toxic metal might be found in any book printed before 1985. . . .

Implementation of the new law has libraries and secondhand bookstores reeling. Although they could pay to have each old book tested, the cost ($300 to $600 a book, according to the American Library Association) makes that impractical.

For more on this, see Walter Olson's City Journal article, "The New Book Banning," as well as his stuff on Overlawyered.com, specifically this post.