Don't know if anyone was watching this story, but after passing a law requiring autographed items to bear authenticity certification (especially things like autographed sports equipment/memorabilia), the legislature has backed the law off a bit to exempt signed books after booksellers complained that book-signings and other author events would be severely compromised:
http://www.sfgate.com/news/article/California-bookstores-exempt-from-autograph-12282700.php
http://www.sfgate.com/news/article/California-bookstores-exempt-from-autograph-12282700.php