That was the dumbest thing about "Death Note". Dipshit Light wasted his time on writing the names of people that were already being ground up by the criminal justice system. He was so cop-brained that he never could even imagine using this power on the guys who are above any justice whatsoever. If he made a list of the wealthiest labor-thieves and cruelest dictators, would anyone even bother going after him? If he post-dated it to all go off at once, there would be zero pattern for any detective to start from.