Very, very scary. These remind me of these plastic spikes I saw at a gun show a few years ago designed to allow insane people to get past metal detectors with sharp implements.
This is a knife made of G10 laminate, which is usually used for circuit boards. It holds an edge very well and can be hidden behind a credit card or shaped to fit inside a
menpen. They are virtually undetectable—although the folks who make them here in the U.S. are working with the government to figure out how to detect them—and are primarily designed to allow police and special agents a last ditch weapon if faced with a tough situation.
Chameleon Weapons Defy Detection [DefenseTech]