In some countries, Japan for instance, it's illegal to film people without their permission. Exceptions are made for crowds and of course most people don't pros

In some countries, Japan for instance, it's illegal to film people without their permission. Exceptions are made for crowds and of course most people don't prosecute, especially if they don't notice, but it is illegal. Tangentially related, it's interesting to go to a Japanese trade show, a place where it would seem like their entire motivation is to show stuff off, and yet you'll see booths saying "no photography".