The lithium ion batteries that power hoverboards are dangerous and if overheated, can burst into flame. Until another power source can be used or until these highly volatile batteries can be manufactured to be more safe, hoverboards and other objects should be removed from the market due to the dangers that they can cause and the high risk of injury, especially in young children.
Apparently, there has been a sharp increase in the number of fires involving hover boards. It seems the issue is with the lithium-ion batteries along with the fact that many are made in China under unregulated conditions. If they cannot be made to perform in a safe manner, then they should be taken off the market until the issue can be resolved.
I believe the debate should be geared more towards the fact of why are they are unsafe. Followed closely by why they are still on the market in an unsafe condition, if the known cause of the fires can be corrected and any cost and perhaps a severe penalty be applied to those being unsupervised and under age.
Nearly all of these two-wheeled, battery-powered toys are made in China, many in the cheap tech manufacturing hub of Shenzhen. Already millions of hoverboards have been shipped out of China this year—in October alone, 400,000 shipped from Shenzhen (link in Chinese). That explains the deluge of identical-looking hoverboards on Amazon and at other retailers. While many have unique brand names and tiny differences in detailing, the vehicles are nearly identical. In some cases they are just that—manufactured by CHIC or another Chinese company, and branded especially for an importer.