It's not considered a weapon, it's considered more dangerous than a weapon. Apparently Americans have a higher chance of choking on the "toy" parts of the egg than shooting themselves with a firearm.
(Yeah, I don't understand this either. Just, WTF.)
I live in the US and one time, when I was in high school, one of my brother's friends came up to me and was like "Shh... don't tell anyone..." And handed me a kinder egg, then walked in the opposite direction.
(Yeah, I don't understand this either. Just, WTF.)
But if i bought one now, everyone would be like "hey, you're not a a kid anymore!"