Broad web surveillance prevents terrorist attacks  Over the last ten years, and right up to the present day, the most important national security interest of the United States has been preventing terrorism. A fight against terrorism requires a large amount of resources invested in tracking terrorist networks and in finding those who may turn to terrorism. Intelligence gathering cannot just focus on those we already know to be terrorists as people can easily become radicalised while not meeting any individuals already considered to be terrorists. This means that there needs to be a broad brush intelligence gathering operation that finds those who are on the path to terrorism. This is why operations like PRISM and xkeyscore are so important; they allow the United States to find people who are being radicalised by material online or those who are just working out how to launch an attack themselves. The NSA Director Keith Alexander has stated that the surveillance has helped prevent “potential terrorist events over 50 times since 9/11.”, with PRISM contributing to 90% of the information on these plots. As only 10 were domestic the surveillance is a benefit to other countries as well as the United States. [1]  [1] Nakashima, Ellen, ‘Officials: Surveillance programs foiled more than 50 terrorist plots’, The Washington Post, 18 June 2013,