Prevent users from starting multiple accounts?

Question

I know that in the end it, can\'t be done.

But, what are the options to:

  a) limit the options for persons to create multiple accounts,
  b)

Answer 1

You can set a cross browser cookie e.g. http://samy.pl/evercookie/ (flash cookies) The can not be deleted by the browser cookie deletetion they stay 4 ever and you can read the cookie cross browsers. Its the ultimate solution if the user uses the same computer. With more than 1 computer the IP address is your only way to find out, but (in my case) sometimes 2 real people in the same house with 2 computers login 2 my website