In Germany it's generally illegal to film people apart from certain exceptions (mostly public events and public spaces). Even when filming something in public,

In Germany it's generally illegal to film people apart from certain exceptions (mostly public events and public spaces). Even when filming something in public, you must be filming the event/space and not a person or group who happens to be occupying it, which is a fine distinction. Even surveillance cameras have strict requirements to be legal. You don't want to be the guy who goes to jail for having a surveillance camera, right? Tangentially, nightclubs put stickers over your phone cameras and that is a great idea.