Thanks to former NSA man Edward Snowden, we now know a fair amount about the NSA's ability to collect data about what people do online, and it's all rather disturbing.
But the future looks even more worrisome. Some of the biggest companies in tech are assembling new forms of online tracking that would follow users more aggressively than the open technologies used today. Just this week, word arrived that Microsoft is developing such a system, following, apparently, in the footsteps of Google.
The new data troves are to be used for advertising, not government surveillance, and only made available to authorised third parties. Yet the NSA has proven adept at co-opting large pools of data for its own ends.
"Users did not have much control in the cookie era," says Marc Rotenberg, executive director of the Electronic Privacy Information Center, a nonprofit advocacy group in Washington. "But the problem is about to get much worse -- tracking techniques will become more deeply embedded and a much smaller number of companies will control advertising data."
Rotenberg says potential NSA use of the next-generation tracking data is all the more reason to move away from behavioural tracking. And he points out that there's already evidence that ad data could have been used by government spies. NSA documents published by the Guardian earlier this month appear to postulate that cookies set by the pervasive Google-owned ad network DoubleClick could be used to spot internet users who also use the Tor anonymity system.