After five years, who to blame ? And how old instawallet users woke up after five years ? If you spent few bucks before five years to fulfill your instawallet then forget about it,now you would a lot of money to get the same amount .
If Boussac doesn't hold old funds, then i doubt he can pay everybody even he wants to . From other side, he would also verify the real old users before to pay anything .

Anyway, we still need his opinion about this as he didn't set a limit period to payback users and there is no reason for him to ignore several claims. TryNinja affirmed that he didn't get any response from Boussac after a long period from sending him PMs about the situation.