Washington, May 27 (PTI): ''Cloud'', ''team'' and ''Mexico'' -- these are some of the words used by government spies to scour the social networking sites and online media for evidence of threats to the US, it has emerged.

The intriguing list, released by the US Department of Homeland Security under the Freedom of Information Act, also includes obvious choices such as "attack", "al-Qaeda", "terrorism" and "dirty bomb", the 'Daily Mail' reported.

Department chiefs were forced to release the manual following a House hearing over documents obtained through a Freedom of Information Act lawsuit which revealed how analysts monitor social networks and media organisations for comments that "reflect adversely" on the government.

However, they insisted the practice was aimed not at policing the internet for disparaging remarks about the government and signs of general dissent, but to provide awareness of any potential threats.

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.