This one makes sense. Can't we just restrict the use of the account to one particular IP? By doing so we can make sure that they don't sell their accounts right?
We could, but it almost certainly won't happen. People can just use a new connection or a proxy though. I've suggested in the past that once you create an account here that IP is burned and can no longer be used to create one (without maybe paying a fee).
Or what if we do this? When they join the forum we can let them choose three ip's of their choice and we can make a rule to only use their account from those IP's. By doing so we can stop them from selling their accounts right?