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This piece originally appeared at the .

The US government's web of surveillance is vast and interconnected. Now we know just how opaque, inefficient and discriminatory it can be.

, you can be pulled into the National Security Agency's database quietly and quickly, and the consequences can be long and enduring. Through ICREACH, a Google-style search engine created for the intelligence community, the NSA provides data on private communications to 23 government agencies. More than 1,000 analysts had access to that information.

This kind of data sharing, however, isn't limited to the latest from Edward Snowden's NSA files. that the FBI shares its master watchlist, the Terrorist Screening Database, with at least 22 foreign governments, countless federal agencies, state and local law enforcement, plus private contractors.

and includes both foreigners and Americans. It's also based on loose standards and secret evidence, which ensnares innocent people. Indeed, the standards are so low that the US government's guidelines specifically allow for a single, uncorroborated source of information – including a Facebook or Twitter post – to serve as the basis for placing you on its master watchlist.

To keep reading the full column on the Guardian's Comment is Free page, click.

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