>>967161
Meta data analysis.
Google has my phone numbers. Even if I live under a rock and only have a landline, people I know have my number and there is a public record of my existence. Using simple logic across a person's contacts, locations, and who they are near - a recorded transcript of a conversation can be used to build a history and profile of others.
Prism is database level access to the various social media platforms, and Snowden seems to be involved with that system. Perhaps Google and co. Found or were sold ways to make Prism a two-way street and each could access each other's databases (or… Just contractually agreed to do so).
The end result is that location data combined with WiFi contact data can be used to map the location of hardware. In certain examples, where a MAC can be obtained, a person logged in on both their phone and a workstation can actually geolocate that workstation and anyone who uses it. Even if not, networks with WiFi nodes can be generally located to the physical location of the WiFi node.
If any target individual is known or suspected to pass through these zones, microphones and cameras could be activated in pursuit of additional information. An 'off grid' person can be targeted via friends or family with phones, computers, or any networked hardware they are suspected of interacting with.
Today's processing power allows phones to process transcripts of conversations, and multi-mic setups allow for processing through cross-talk. The transcript can then be analyzed for information deemed relevant to various subjects and appended to their meta-data dossier.