Effects of the Patriot Act on Librarians

Quaryon writes "The Patriot Act apears to have some chilling effects with respect to libraries and booksellers. An FBI agent can get a warrant, without any evidence, in order to compel a librarian to reveal lending details on a suspect. The librarian cannot tell anyone about the search, including the target of the search, and the details of how many such searches are done are not made public. Articles at SFGate News and Common Dreams give more details." We had a related Ask Slashdot a few weeks ago.