A convoy of four spotless, unmarked white passenger shuttles rolls down the middle lane doing 65 mph. The windows are heavily tinted and the sides have no markings. None of the vehicles has front or back plates. There are no temp plates in the windows.
Harmless? Probably. But you couldn't shake the feeling that if you asked the wrong person where those shuttles were going, you'd end up in one of those shuttles going someplace you wouldn't want to go.