And if you aren't worried, maybe you should start. Google records and analyzes data about anything you send it--searches, translations, map requests, online reading-- and the company appears (at best) ambivalent about the value, or even the possibility, of confidentiality. This month Google forcefully defended the privacy of Gmail users against Chinese government snooping. But last month, its CEO, Eric Schmidt, sounded pretty cavalier about Google's own spies, or those of the United States government. "If you have something that you don’t want anyone to know," he infamously said, "maybe you shouldn’t be doing it in the first place." And he added that search engines "are all subject in the United States to the PATRIOT Act and it is possible that all that information could be made available to the authorities."
Marlinspike, who is a programmer, security researcher and sailor (he makes part of his living delivering yachts), puts it succinctly on his site: "Google thrives where privacy does not.'' Hence, Googlesharing, which routes your traffic through a proxy server that presents a bunch of false identities to Google. [Update: 1/24: It's working again, after being down yesterday.] Each time you ask for something, you go through a different identity. So, to Google's all-seeing eyes, your traffic is scattered among many different "people," and each "person" is actually a composite of several real human beings. (Obviously, this won't work if you've identified yourself by logging in, so it doesn't block tracking of Gmail or Calendar.)
Andy Greenberg at Forbes.com described the add-on in his story yesterday, where he also noted that for serious anonymity, users have to turn to Tor or a similar service. Those methods, Marlinspike says, slow down your browsing. His simpler and faster approach won't completely cloak you. And of course does nothing about the data-collecting done by Bing, Facebook, your cell-phone company and others. But it's a start.