"When we look at the full-on mass surveillance watching everyone in the country, in the United States, it doesn't work. It didn't stop the attacks in Boston. The marathon bombings. Where again, we knew who these individuals were. It didn't stop the Underwear Bomber, whose father walked into an embassy and warned us about this individual before he walked onto an airplane. And it's not going to stop the next attacks either. Because again, they're not public safety programmes. They're spying programmes. They are valuable for spying."