There's some of that, a lot of it though is e-dirtbikes that can pretty easily do 35+mph stock and 50+ with light modifications. A friend of mine has one and I've ridden it. It's a motorcycle with mountain bike brakes. I don't think they're bad vehicles, but I do think they should be treated as motorcycles as opposed to bicycles, and 13 year olds shouldn't be riding them on public roads.