“Contact chaining analysis,” what the NSA did with the networks of relationships disclosed by the bulk Internet metadata it collected from ~2001 to ~2011, according to a draft of a 2009 report by the NSA’s inspector general.
In case you were wondering, the IG report defined contact chaining as
“the process of building a network graph that models the communication (e-mail, telephony, etc.) patterns of targeted entities (people, organizations, etc.) and their associates from the communications sent or received by the targets.”
“Additional chaining can be performed on the associates’ contacts to determine patterns in the way a network of targets may communicate. Additional degrees of separation from the initial target are referred to as ‘hops.’ For example a direct contact is one hop away from the target. A contact of the direct contact would be described as being 2 hops away from the target. The resulting contact-graph is subsequently analyzed for intelligence and to develop potential investigative leads.”
The inspector general’s report said internet metadata was one of four types of domestic and international data vacuumed up by the NSA between ~2001 and ~2011. With occasional stops and/or restarts of one or the other category due to technical problems or legal concerns on the part of e.g. the FISA court, the NSA acquired: internet metadata, telephone metadata, internet content and telephone content.
(Con TALKED kett en KLAH shtell en.)