Drove today, but on the ride home yesterday, I was buzzed on the MUP by the rider of a pocket bike

heading the opposite way... doing 20+ mph, I'm sure, with a second person riding on the back!

So these pocket bikes cost about the same thing as bicycles or even a little less, but they burn gas (-1) and require no effort on the part of the rider (again, -1). These can be real menaces when used in the wrong contexts - that is, almost any context. (They shouldn't mix it up with traffic of any kind, motorized or otherwise.)