Kudos to John Cape for suggesting something be done to educate younger bike riders. Something should be done.
I've seen all of the problems he mentioned and had to keep from killing more than one foolish child behaving in one of those manners. However, I don't think John's suggestion goes far enough.
I've met and passed many "serious cyclists" on the county roads. You know the ones - dressed in spandex, wearing matching helmets, sometimes actually going fast enough not to be an impediment to traffic. I've also met many who think they can't be hurt in a car bike collision and act just that way, blocking traffic, insisting on "their space in the road." These types may some day be totally in the right when they are hit by a car. Let's hope they don't end up dead right.
The story that always comes to mind is the one my wife tells. She moved into the left lane to go around a couple of spandex bikers, who insisted on riding double in the lane. They began screaming at her about crossing a double yellow line to pass them. At the next intersection, they passed her at the stop sign without so much as a hesitation, blew through the intersection in front of cars already waiting for their turn to go. They didn't stop, they didn't wait their turn for the right of way, it seems they only want cars to obey the laws on the road, they don't need to do so.
I propose that every bike rider need a license and that their bikes be equipped with the same dual-colored triangle that farm equipment and buggies need to have. The newer farm equipment does 25 mph in road gear and they still need the triangle, why not bikes? From where I sit, it's the bicyclists causing the problems that they then complain about. Let's make sure that they know the rules of the road, let's insist they pass a test and be licensed.