CPSC bans sale of BuckyBalls
reuters.com
reuters.com
Hot stoves, grills and harmful toxins aren't toys and there isn't a normal use case where a child would use those. It can happen, but it's not intended.
A toy's use case is playing with it. This particular toy is causing problems, where other toys aren't. I see no problem in banning them. We aren't a full-on libertarian society, we make choices, not always to everyone's liking.