In the age of endless sharing, super cookies, social search results, and that ever-present social graph, it’s comforting to know that there are some who are still prioritizing privacy. (And a few of them are former Googlers no less!) In October 2010, Google engineer Brian Kennish created Facebook Disconnect, a Chrome extension that disables all traffic from third-party sites to Facebook servers but still allows you to access Facebook itself. The extension was an immediate hit, racking up 50K active users in two weeks (it now has 200K+), prompting Kennish to leave his job at Google to focus full-time on helping the average web user take back control of their data.

Shortly thereafter the former Google engineer launched Disconnect, applying the same method behind Facebook Disconnect to other major third-party sites, like Digg, Google, Twitter, and Yahoo, enabling you to disable data tracking while you browse.

Now collectively attracting over 400K weekly active users, Kennish tells us his privacy-protection tools ended up being much more popular than he ever expected. As a result, he decided to turn the side project into a real company, co-founding Disconnect with another ex-Google engineer, Austin Chau and consumer rights advocate Casey Oppenheim.

The company, which officially launched late last year, is founded on a simple premise: Personal data should belong to people, not corporations. So, the team is building Disconnect into a full-fledged platform that allows users to control who does what with their data online, Kennish says. The first step is to help users stop the free flow of personal information to third-parties, he says, while step two will be giving users customized controls that allow them to share personal info when and how they deem fit. (To give you a sense of how big he thinks this problem is, watch this video here.)

To help them in their crusade, the team has raised $600K in seed funding, led by Highland Capital Partners with participation from Charles River Ventures, and angels investors like David Cancel, Mark Jacobstein, Ramesh Haridas, Vikas Taneja, Chris Hobbs, and Andy Toebben.

Both to celebrate their new raise and to provide users with a response to Google consolidating its privacy policy (which, in fact, rolled 70 different policies into one, allowing the company to combine all data it has on you into a single profile), the team is launching Google Disconnect and Twitter Disconnect for Chrome, Firefox, and Safari.

These extensions are similar to Facebook Disconnect and follow the recent addition of Facebook Disconnect to Firefox and Safari. And, of course, some may also be familiar with Kennish from Frictionless, which he built with Nik Cubrilovic to take having to download a Facebook app out of the process of reading news on the social network. (Read John’s coverage here.)

The app was an awesome solution to a grievance many have experienced when reading news social network-style, and Kennish says he expected the extension to get some traction, but it only had about 3K active users at its peak, and with Facebook iterating on its UI, Kennish said they had trouble keeping up, and decided to put the app “in hibernation.” Although, with some pressure, we may be able to convince the guys to bring it back.

In the meantime, Disconnect is going to be focusing on protecting you from the thousands of companies that track, analyze, and auction off your browsing and search histories without so much as a peep to you or the millions of other web surfers out there. And, by the way, Disconnect doesn’t collect your IP address or any personal info, unless you want to give them your email address, of course.

This is also especially relevant given this post from Gizmodo today about nuking your search history and the case against Google.

For more, check them out at home here.

Update: One thing we should address: We’ve received a few tweets accusing Disconnect of being “hypocritical,” because its extensions appear to (in spite of what’s written above), actually seek permission to access your data themselves. It would be pretty funny if a company that purports to help you keep your data out of the hands of auctioneers is actually the one collecting all your data, right? No.

However, this reaction is understandable, considering it’s true that Disconnect’s Chrome install dialogue, for example, makes it seem like the extension is preparing to steal all your data, and warnings are indeed triggered. (See Brian’s explanation here.) But, rest assured, Disconnect is doing anything BUT surreptitiously scraping all your data. In fact, to reiterate, they collect no user data whatsoever.

If that day should come when they do, we will inform you (or maybe even post the addresses of all co-founders so that you can go egg their houses), but until then, you may just want to thank them for making some incredibly helpful privacy tools. Or not, just a thought.