Revealed: Words to avoid using online if you don't want the feds spying on you

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’.