A 2013 NSA document shows that comprehensive MYSTIC harvesting of telecommunications data in the Philippines is carried out by the Australian Signals Directorate, formerly known as the Defence Signals Directorate, which is a so-called "5-eyes" partner with its American counterpart.

Through an operation codenamed VENATOR, Australian and US access to Philippine telecommunications data is provided "via [a] DSD asset in a Philippine provider site" which collects "Philippine GSM, Short Message Service (SMS) and Call Detail Records." GSM or "Global System for Mobile" communications is the most widely used digital cellular communications technology in the world today.

In 2013 the NSA noted that the covert Australian monitoring operation "will soon become a source of lucrative intelligence" about "terrorist activities in Southern Philippines".

However, the leaked documents also make it clear that MYSTIC intelligence is collected not by targeting individual suspects but through the bulk collection of telephone call data across entire networks and countries, as well as international telecommunications traffic.

The documents show that MYSTIC operations cover the Philippines, Mexico, Kenya and another country the name of which has been redacted by The Intercept.