An old law has come to the forefront, and it's being applied in a way that could affect what you do on your PC. In a case close to the Boston Marathon bombings, a federal court will decide if the deletion of browser history was an obstruction of justice.
http://rt.com/usa/266389-browsing-history-obstruction-justice/
http://rt.com/usa/266389-browsing-history-obstruction-justice/