<p>SAN JOSE, Calif. Just as Prohibition drove drinkers underground in the roaring'20s, the music industry's crackdown is pushing many song swappers away from the open Internet and into what amount to cyberspace speakeasies.</p>
<p>These high-tech Cotton Clubs usually require users to be trusted or at least know someone inside. The files, instead of out in the open, are encrypted - the 21st century equivalent of hiding bathtub gin under a fake floorboard.</p>