Boundless Informant: the NSA's secret tool to track global surveillance data

Revealed: The NSA's powerful tool for cataloguing data – including figures on US collection

• Boundless Informant: mission outlined in four slides
• Read the NSA's frequently asked questions document

The National Security Agency has developed a powerful tool for recording and analysing where its intelligence comes from, raising questions about its repeated assurances to Congress that it cannot keep track of all the surveillance it performs on American communications.

The Guardian has acquired t...