Make of this what you will... I thought it was interesting!

What's in your pocket? What's in your shop?

U.S. Customs has proposed revoking earlier rulings that assisted opening
knives are not switchblades. The proposal would not only outlaw assisted
opening knives, its overly broad new definition of a switchblade would also
include all one-handed opening knives and most other pocket knives... Seems
that our utility knives and other knife tools are covered under this too.

"It is now CBP's position that knives incorporating spring- and
release-assisted opening mechanisms are prohibited..." from
http://www.kniferights.org/U%20S%20C...g%20Knives.pdf

I found this stuff mentioned in a gun rights e-mail and followed the path to
http://www.kniferights.org/

John