The Department of Homeland Security has been forced to release a list of keywords and phrases it uses to monitor social networking sites and online media for signs of terrorist or other threats against the U.S. The intriguing the list includes obvious choices such as 'attack', 'Al Qaeda', 'terrorism' and 'dirty bomb' alongside dozens of seemingly innocent words like 'pork', 'cloud', 'team' and 'Mexico' and first came to light in a story by The Daily Mail.