Homeland Security research pt. 3

FOX News webpage

Reading this article opened my eyes to how concerned the majority of American residents really are about terrorism and keeping our country safe. In fact, fifty-eight percent believe that President Bush has the authority to monitor electronic devices used for international communication...six in ten even reported that they're "ok" with the National Security Agency (NSA) listening on their international phone calls. Correspondingly, over half of US citizens believe that the monitoring has helped towards the prevention of terrorism, and a similar number think extending the act is a good idea. "About half of the public (46 percent) attributes the absence of a terrorist attacks in the United States to the success of security measures, while 22 percent think it is more likely that no new attacks have been planned since 9/11 (20 percent say it’s some of both)."
However, many Americans also believe that the wiretapping is quite the invasion of privacy. A poll of 900 registered voters for FOX News concluded that nearly six in ten say they are "concerned that government efforts to track terrorists are harming the civil liberties of American citizens."


Questions:
- Have the NSA actually found any material while monitoring calls regarding potential terrorism or any other threats to the safety of the US?
- Does the NSA screen all international calls? Is it random? Could they have listened to just anyone's phone calls?