I'm not sure I agree with you, ck, regarding your First Amendment analysis. The Ninth Circuit emphasized regulation of speech, not regulation of brothels, in its opinion regarding the Nevada law. And while there's generally First Amendment protection for commercial speech, there isn't when the commercial speech promotes an illegal activity. In the Nevada case, the Ninth Circuit wrote: "
Central Hudson [Gas & Electric Corp. v. Public Service Commission, 447 U.S. 557 (1980)] specifies that if the regulated speech concerns illegal activity or is misleading, the First Amendment extends no protection and the analysis ends." Thus, there's no First Amendment protection for prostitution ads in those places where prostitution is illegal (i.e., all of the U.S. but two counties in Nevada).
Here's a link to the opinion:
http://cdn.ca9.uscourts.gov/datastor...1/07-16633.pdf