[petsfed]

So long as the pedals are hooked up to the drive train in such a way that they actually work, I don't actually have any complaint.

If the user can easily switch to backup-pedal power to traverse e.g. Millenium Park in Chicago, then I don't really see the problem. Certainly, failure to use that function is a problem, but I don't think its good for society if we allow police to stop actual bicyclists on suspicion of riding a pedal assist vehicle. These things are pretty obvious when in use: bikes don't coast, unassisted, uphill at the speeds these things frequently achieve.