My town (Boulder, CO) is inundated with what look like 12-17 year-olds absolutely tearing around on e-bikes. They are rarely petaling and often going 20-30 mph. I assume they have just defeated the speed governors. It's essentially underaged, unlicensed motorcycle riders that use both roads and paths as it seems convenient. One of the fundamental safety problems is that although people are very used to cyclists here, they are not used to the car-like speed that these things go.