https://www.theguardian.com/uk-news/2014/jan/31/footage-released-guardian-editors-snowden-hard-drives-gchq
On the instructions of GCHQ, the trio bought angle-grinders, dremels – a drill with a revolving bit – and masks. The spy agency provided one piece of hi-tech equipment, a "degausser", which destroys magnetic fields, and erases data. It took three hours to smash up the computers. The journalists then fed the pieces into the degausser.
