Originally Posted by shandude
The VB admins have acces to some mods named "Multiple registratinon detector" and "AE Detector". Now the 2nd mod actually stores a cookie in your machine. If it sees the cookie on your machine and you register a different account then you will get caught. So always use Opera or Firefox (Preferably Opera) for your adventure and be sure to block any cookies from the site you are going to register.
Can anyone confirm this?
Would want to know more about this advance method too.

I surf using a proxy all the time, my browser hides its own user agent (type and information are all fake), clear all my history, cookies and temp contents upon exit but still my multiple accounts could still be detected.

Are there any methods which I'm not aware of?
MAC ID is not possible because only the isp have access to them under the same subnet.

Someone above suggested machine ID?
Could that be possible?

One method is by matching your browser's HTTP header and user agent information.If multiple accounts have the same information logged that matches exactly with one another, it should give hints that they are most likely clone accounts.