Yes and I would like to add: "It's always argued that what you do in public carries no expectation of privacy, but that statement is somewhat meaningless when you consider the number of plates ALPRs scan and store."
This is akin to the two of us in a park. If I am taking a picture, you have no expectation of privacy, not just because it is public, but also because you have the freedom to move away from me. A little different situation if I start following you though.
"How it became a fad, I'll never understand. but then, no fad actually makes any sense." I know nothing of the game, but apparently it is very hard to play. I expect it was the challenge that made it a fad.