mass murdur at Akihabara, Tokyo, Japan

A man of 25 drove his rental truck into pedestrians last Sunday. After stopping the truck, he ran into to people with survival knife of 13cm blade in his hand and started stabbing those hit, and others around. 7 died and 12 other injured. He was finally corned by policeman and arrested on the spot.
Upon investigation, he said that he had troubles at work and got tired of the world. Being lonely all the time, he wrote many posts to online blackboards, and even announced his plan, writing live reports about his preparation, road condition (on the way to Akihabara) and final goodbye message before the killing.