According to The Wall Street Journal (WSJ), Twitter has cut off US intelligence agencies from Dataminr, a service that analyses the entire output of Twitter posts. One senior intelligence official told WSJ that the social media firm 'appeared to be worried about the "optics" of seeming too close to American intelligence services.' Twitter explained that it has a long-standing policy that forbids third parties (such as Dataminr) to sell its data to government agencies for surveillance purposes. In a statement, Twitter said that its 'data is largely public and the U.S. government may review public accounts on its own, like any user could.' Security and privacy issues continue to heighten tensions between Silicon Valley and the US government.