Others have said most of what I’d say, but I’d just add that the danger of an item heavily depends on context. There are any number of items people regularly take on airplanes that, in the right context, could be dangerous. But the blanket removal of all such items from every person, without consideration of whether it actually poses a threat to the passengers of the craft in a reasonable situation, is just lazy.
Now, having said that, there is the possibility that it might run afoul of concealed weapon permit requirements (or other weapon legality issues) depending on location. But just taking it away because it’s “dangerous” is a cop-out.
