Link 1: Revealed: the day Guardian destroyed Snowden hard drives under watchful eye of GCHQ - video | World news | theguardian.com

On Saturday 20 July 2013, in the basement of the Guardian's office in Kings Cross, London, watched by two GCHQ technicians, Guardian editors destroyed hard drives and memory cards on which encrypted files leaked by Edward Snowden had been stored. This is the first time footage of the event has been released
Link 2: Footage released of Guardian editors destroying Snowden hard drives | UK news | theguardian.com