It is fairly  difficult to determine if a person has multiple accounts if those accounts do not use a common item such as an email address.  You can easily set up an number of email accounts on the free sites such as Yahoo and Google.  Then use those accounts to get you user id's from the ADN.  With those accounts and multiple window you can move from one window to another and post as different accounts.  It not quite that easy but it can be done by anyone who is willing to spend some time getting it set up.