browser history.pngOne piece of information a lot of places are clamoring to get their hands on is what other websites their visitors are viewing. By having access to this information they would be able to determine what social networks you use, what search engine you prefer, and more. As it turns out any site can grab this information from your browser, but there’s one little catch.

SocialHistory is a simple JavaScript file that has developed a way for website developers to obtain this information, but they’re trying to use it for good. By default it will look to see which, if any, of the popular social sites a particular user visits so that relevant buttons/links can be displayed. For example, if a user has never visited the bookmarking website it’s probably safe to not display the “add to” button.

Eerie, huh? How can it get this information from your browser’s history? What it does is display a list of pre-defined links in an iframe which point to user-supplied sites. Using JavaScript it then analyzes the color of the link, and if it’s purple it will know that you’ve already visited that site. If it’s blue it knows you haven’t visited it.

This is making use of a standard web browser feature that makes it possible for the user to distinguish which links/sites they’ve visited, and so it really isn’t a vulnerability. Luckily this doesn’t spit out information like how many times a user has visited a particular site, but I’m sure that won’t provide too much comfort to you.

The catch? As you might have realized by now this will only work using a pre-defined list of sites, and it can’t actually crawl through your browser’s history. That’s not stopping people from implementing it though. Using SocialHistory this site has already put together a system that will guess whether you’re male or female based upon the sites you visit. It says that they’re not storing any of the data, but I’m sure other sites who are trying to sneakily gather the stats won’t be so forthcoming about their intentions.

[via Webware]