I love this marketing.
What I tend to do is leave my camera hanging round my neck and shoot from the hip on autofocus. It saves all that bother when people think you’re taking photos of them. You are, but if people think they’re being photographed, they freeze up, or smile, or wave, or attack.
The effects, since one has to judge where the subject is, can be a bit random, but part of the fun is the surprises at the end of the day.