https:// www.thecipherbrief.com/five-eyes-intel-sharing-unhindered-trump-tweets

The initial UKUSA Agreement, declassified in June 2010, lays out the extent of SIGINT collaboration, including the acquisition of equipment, collection of communications traffic, traffic analysis, cryptanalysis, decryption and translation. The primary bodies of the intelligence partnership are the U.S. National Security Agency (NSA), the UK’s Government Communications Headquarters (GCHQ), Australia’s Defence Signals Directorate (DSD), Canada’s Communications Security Establishment (CSE) and New Zealand’s Government Communications Security Bureau (GCSB).

While the agreement initially began with SIGINT cooperation, it has since expanded to include sharing and cooperation in fields such as human intelligence, covert action, counterintelligence, geospatial intelligence, law enforcement, and finance and transportation security.

A prominent example of the Five Eye’s joint SIGINT collection comes from the so-called Echelon program, which reportedly began in the 1960s and involved the interception of civilian satellite communications based on keywords submitted by each alliance member.

A more recent example of how Five Eyes might collect SIGINT with geographic implications would be through downstream collection of communications data at rest from domestic internet companies and upstream collection of communications travelling through domestic internet service providers. This collected data can then be reportedly mined directly by all Five Eyes partners through programs such as XKeyscore, no matter which party actually collected the data.

According to the initial agreement – which is reported to have evolved with the times with the current document remaining classified – all raw SIGINT traffic and intelligence products are shared relatively freely unless a party chooses to forgo sharing or receiving specific intelligence. There is a mutual understanding that the citizens of Five Eyes countries will not be targeted for collection by another member agency, and if such communications are incidentally intercepted, there will be an effort to minimize the use and analysis by the intercepting state – such as by labeling it with “UK Citizen” or “Canadian Company.”

However, according to a leaked 2005 NSA document, under certain circumstances, Five Eyes members may conduct unilateral collection against the citizens of other members should collaboration with that member be declined. But any collection, processing and dissemination of that information must be maintained in NOFORN (“No Foreigners”) channels. This means that Five Eyes partners cannot, as both a matter of policy and legality, help each other bypass the privacy protections of their home countries.