I am playing a browser based online game and is wondering how it can detect I am trying to login using 2 separate accounts on the same machine.
I've tested a few things. First it is not based on detecting same IP since I can login concurrently using firefox/IE and it wont be a good idea to ban users sharing the same IP using a router (say students inside a University). It is when I am using 2 IE windows that it can detect.
I also tried IE8's New Session feature. To my surprise, it is still able to detect 2 concurrent IE8 even if I explicitly started a new session. Does it mean some cookies are still shared even if I start a new session?
In IE7, I tried starting 2 IE processes which should NOT share any cookies. But it is detected.
What are the possible ways it can use to detect multiple login? I also want to incorporate such feature in my appl.