As well as terrorism, analysts are instructed to search for evidence of unfolding natural disasters, public health threats and serious crimes such as mall/school shootings, major drug busts, illegal immigrant busts.

The list has been posted online by the Electronic Privacy Information Center – a privacy watchdog group who filed a request under the Freedom of Information Act before suing to obtain the release of the documents.

In a letter to the House Homeland Security Subcommittee on Counter-terrorism and Intelligence, the centre described the choice of words as ‘broad, vague and ambiguous’.