I admit I only galnced at the site, if they are not saying how they achieved their supposed goal then I'll pass. Tend to agree with kartal
I think if you are a real tech head you would never even let this site to tell you where you have been, they are using a trick to get you browsing history?
and Jimdoria is likely right
JavaScript runs in the browser, and has access to the same info the browser does. The program runs in YOUR browser, gets information from YOUR browser and shows it TO YOU. How exactly is this a security breach?
Ultimately though one can trick browser to read and/or intercept info but that's hardly anything new and up to browser and web app makers to patch holes