Personally I think it should be the other way around, the default should be out with the opt-in available - you or an approved next of kin should have to specifically authorize what happens to your remains - if no one or there are any doubts, then no action should be taken on the remains - feels over the line to me...I'm curious - how do they square this with certain religions who have specific burial customs or beliefs that are conflicting? if someone of that faith somehow dies without opting out are they just going to be defiled?