Auf einer kanadischen Seite habe ich das hier gefunden:
U.S. Customs and Border Protection
Very specific U.S. regulations govern what you may bring into the United States. These cover gifts, alcohol, tobacco and vehicles. Also included are various prohibited and restricted items such as lottery tickets, liquor-filled candy, seditious and treasonable materials, obscene or pornographic materials, products made by convicts or forced labour and products, such as ivory, made from endangered species. Switchblade knives are prohibited, except those owned by persons with only one arm.
Danach sind nur Springmesser verboten.
Ciao,
Stefan