In 2023, a 17-year-old boy in Japan licked a shared bottle of soy sauce and got sued for $480,000. This incident highlighted just how much daily life in Japan relies on a trust between strangers to behave around communal items. It happened at a branch of Sushiro, Japan's largest conveyor-belt sushi chain, in Gifu. A friend filmed the boy putting his mouth on the nozzle of a communal soy-sauce bottle, licking a clean teacup and putting it back on the stack, and then using his finger to spread his saliva on sushi as it went past on the conveyor belt. The video went viral, and the nation coined a new term: sushi terrorism. The conveyor-belt sushi system was invented to get by with no waiting staff at all. In the 1940s, Yoshiaki Shiraishi, a sushi-bar owner in Osaka, struggled to hold on to young apprentices who were being lost to overwork. He watched a conveyor belt carrying bottles in a beer factory. In 1958, he opened the first sushi restaurant where food was delivered to customers on a conveyor belt. The reason the sushi is so cheap is that you aren't paying anyone to wait on you. You take the dishes off the conveyor, grab a cup from a stack, and there's already soy sauce sitting at your seat. Japan does this all over the place. By 2023 there were some 1,400 unmanned dumpling shops. At the biggest chain, customers pay 1,000 yen, around $7, by placing cash in a box like those at shrines. A Japanese technology journalist noted that the shops rely on one premise: that nearly everyone will not steal from them. In Japan, they call this belief seizensetsu, a belief in the goodness of people. This works if nearly no one takes advantage. But a phone changes the equation. When one person does it once, millions of people can see it. And soon every customer is wondering about the soy sauce. Within a week, Sushiro stopped sending unordered dishes onto the conveyor belt. Kura Sushi, a competitor, added cameras equipped with artificial intelligence over the conveyor belt at all its restaurants. Sushiro sued the boy for 67 million yen, or about $480,000. In July of that year, the case was settled, and the amount he paid remains undisclosed. But the true cost of that one lick was not the lawsuit. So much of Japan's cheap, seamless life relied on the idea that no one needed to be paid to watch. When one teenager with a phone showed the whole country how that trust could be broken, the solution wasn't to bring back human waiters. It was to point cameras at the customers.