I feel like these are frivolous toys that are a net negative to society, but the product has legitimate uses (however silly) and does not cause injury when used appropriately. There are many products in our everyday lives with legitimate uses that can and do regularly injure children but are not banned because we have (at least implicitly) decided that the benefits outweigh the costs. Ultimately this kind of ban is based off a value judgment and it doesn't feel like it is something appropriate for an un-elected regulatory body to decide. The ban should come from Congress.

If a product causes injuries when used as intended then CPSC action seems warranted to me. This is not such a case. I also suspect the lawn dart ban might not have held up in court had manufacturers then pressed as hard as Qu has been pressing today, so I don't think that ban does anything to legitimize CPSC action now. Fireworks bans in the United States have (to my knowledge) originated from legislative bodies.

By the way, the way CPSC reached their conclusion that these magnetic balls were a net negative was based off their own calculation that injuries to children cost more to treat than profits made by the magnetic ball companies. This seems like an absurd way to calculate whether or not something is a net negative to society.