"A group led by a Princeton University computer security
researcher has developed a simple method to steal encrypted
information stored on computer hard disks," reports The New York
Times. It's pretty simple. Memory chips hold data for a short
while after the power is turned off. Cool the chips and they
hold it longer. "Cool the chips in liquid nitrogen (-196 °C) and
they hold their state for hours at least, without any power,"
Edward W. Felten, a Princeton computer scientist, wrote in a Web
posting. "Just put the chips back into a machine and you can
read out their contents." There's a technical paper (PDF) about
it.