Basically you&#x27;re using the specs the browser sends about the computer - OS, screen size, add-ons installed.. this gets pretty unique. I&#x27;ve been able to identify friends on a local site just by knowing them and their computers.<p>Check yourself here:<p><a href="https:&#x2F;&#x2F;panopticlick.eff.org&#x2F;" rel="nofollow">https:&#x2F;&#x2F;panopticlick.eff.org&#x2F;</a>