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Advertisers now stalking users across multiple devices

Advertisers want to compile as much information about you as possible. Tracking where you go, what you click, and how you search is literally their business. They use that data to target ads directly at you, and feed relevant data to their partners.

With the increasing use of tablets and smartphones in daily life, advertisers have been frustrated by a limited ability to correlate traffic from multiple devices to a single person. Well, there is some good news for advertisers, but bad news for privacy advocates. A California-based company by the name of Drawbridge has developed a system that will analyse known data from devices surfing from the same location, and supposedly pick out which devices belong to which user.

The Drawbridge system allows advertisers to target a single person with a specific advertising campaign, regardless of what device they happen to be using at the time. Using a hugely parallel Hadoop infrastructure, it takes the data it has about a person’s online profiles and known locations, and analyses the probability that two devices are being used by the same user. Then, if someone looked up video games recently on their MacBook Pro in Chrome, they’ll get to see ads for Call of Duty on their iPhone.

Drawbridge specifically says that it doesn’t use personally identifiable information, but it is matching first-party cookie data from all of a person’s devices. There is quite a bit of semantic hair-splitting going on here concerning what “personally identifiable” means.

Research has been done about how much data popular websites send to third-party companies, and the results are staggering: “… the Journal examined what happens when people logged in to roughly 70 popular websites that request a login and found that more than a quarter of the time, the sites passed along a user’s real name, email address or other personal details, such as username, to third-party companies.”

Filling out forms truthfully, even on relatively popular and “safe” sites, can be very bad for your privacy.

How to prevent third parties from tracking you

If you don’t want advertisers stalking your movements around the web and compiling a massive amount of data about you, you do have options. First off, there is the Do Not Track (DNT) header. Now available in most browsers, this feature inserts a specific statement in its communication with web servers that asks advertisers to opt the user out. However, there currently isn’t any enforcement of websites to obey the DNT header. Even if there was some sort of enforcement, the shadiest off-shore tracking and ad companies would doubtless still skirt around it.

A large amount of tracking is done via JavaScript and cookies. Extensions like NoScript for Firefox, NotScripts for Chrome, and JavaScript Blocker for Safari give you control over which websites are allowed to run JavaScript in your desktop browser. The selection of JavaScript blocking utilities is more limited on mobile devices, but even Apple’s locked-down Safari browser has the ability to toggle off JavaScript completely when needed. As for cookies, most browsers have the built-in ability to turn off third-party cookies, so you should always use that feature unless you have a specific reason not to.

If you’re really worried about being tracked, you can use a Tor proxy to mask your identity by obscuring your browsing activity. The use of VPNs from other parts of the world will help reduce the ability of advertisers to use geolocation to target you effectively.

If you’re sick and tired of advertisers watching your every move, you can take these steps, and you’ll be in a much better situation. However, the most important way to keep your information out of the hands of these third parties is to refrain from giving it out in the first place.

Whenever possible, use fake names and burner email addresses to keep accounts from being correlated with a single person. There’s no guarantee that the brilliant minds behind these analytics and advertising companies won’t be able to thwart your efforts, but these steps will make their job a lot harder.

Image Credit: Sagie