Intelligence agencies are secretly pinpointing suspects by using the same techniques that advertisers use to track consumers online, according to the latest revelations from leaked NSA documents.
NSA presentation slides released by the Washington Post have given fresh insights into the way intelligence agencies carry out online surveillance, revealing how they use third-party software to bolster their hacking capabilities.
Using a Google-specific tracking cookie known as "PREFID", the NSA and GCHQ are able to identify a web user's browser and single out their communications for the purpose of sending malware to hack the user's computer.
The PREFID cookie is loaded to a person's computer by way of Google products like Search and Maps, even when they are hosted by a separate website. This means that most internet users probably have this cookie.
The use of this cookie in this way is not currently disclosed by Google, though it is possible the tech giant is unaware that the NSA is using it in this way.
On Monday it was announced that Google had joined forces with seven other of the world's largest tech companies to call for wide-spread reforms to US government surveillance, in what is arguably the most significant response yet to the spying revelations from former NSA contractor Edward Snowden.
In an open letter to Washington, the Reform Government Surveillance alliance wrote: "We understand that governments have a duty to protect their citizens," the letter reads, (but) the balance in many countries has tipped too far in favour of the state and away from the rights of the individual — rights that are enshrined in our Constitution. This undermines the freedoms we all cherish. It's time for a change."
Google has yet to respond to the allegations in the report.