I have been asked by a friend that produces a local online publication (small island) if there is a mechanism to stop registered users (paid a subscription) from passing around passwords to other non-registered users?
IP Address's were mentioned etc, but not convinced of that method...

My quickie solution was to auto-generate passwords each month and email the registered user with the new password when the next publication was available. Therefore, stopping password hoarders, but it wouldn't stop users passing on the password.

Any thoughts?