In the attempt to let people know that it may, not only, be sneaky to wear/carry a hidden knife but it may be illegal in your state as it is mine. Here is Connecticut state statute regarding knifes and the hidden knife falls into a couple of categories of illegal!
Sec. 53-206. Carrying of dangerous weapons prohibited. (a) Any person who carries upon his or her person any BB. gun, blackjack, metal or brass knuckles, or any dirk knife, or any switch knife, or any knife having an automatic spring release device by which a blade is released from the handle, having a blade of over one and one-half inches in length, or stiletto, or any knife the edged portion of the blade of which is four inches or more in length, any police baton or nightstick, or any martial arts weapon or electronic defense weapon, as defined in section 53a-3, or any other dangerous or deadly weapon or instrument, shall be fined not more than five hundred dollars or imprisoned not more than three years or both. Whenever any person is found guilty of a violation of this section, any weapon or other instrument within the provisions of this section, found upon the body of such person, shall be forfeited to the municipality wherein such person was apprehended, notwithstanding any failure of the judgment of conviction to expressly impose such forfeiture.
(b) The provisions of this section shall not apply to (1) any officer charged with the preservation of the public peace while engaged in the pursuit of such officer’s official duties; (2) the carrying of a baton or nightstick by a security guard while engaged in the pursuit of such guard’s official duties; (3) the carrying of a knife, the edged portion of the blade of which is four inches or more in length, by (A) any member of the armed forces of the United States, as defined in section 27-103, or any reserve component thereof, or of the armed forces of the state, as defined in section 27-2, when on duty or going to or from duty, (B) any member of any military organization when on parade or when going to or from any place of assembly, (C) any person while transporting such knife as merchandise or for display at an authorized gun or knife show, (D) any person who is found with any such knife concealed upon one’s person while lawfully removing such person’s household goods or effects from one place to another, or from one residence to another, (E) any person while actually and peaceably engaged in carrying any such knife from such person’s place of abode or business to a place or person where or by whom such knife is to be repaired, or while actually and peaceably returning to such person’s place of abode or business with such knife after the same has been repaired, (F) any person holding a valid hunting, fishing or trapping license issued pursuant to chapter 490 or any salt water fisherman carrying such knife for lawful hunting, fishing or trapping activities, or (G) any person while participating in an authorized historic reenactment; (4) the carrying by any person enrolled in or currently attending, or an instructor at, a martial arts school of a martial arts weapon while in a class or at an authorized event or competition or while transporting such weapon to or from such class, event or competition; (5) the carrying of a BB. gun by any person taking part in a supervised event or competition of the Boy Scouts of America or the Girl Scouts of America or in any other authorized event or competition while taking part in such event or competition or while transporting such weapon to or from such event or competition; and (6) the carrying of a BB. gun by any person upon such person’s own property or the property of another person provided such other person has authorized the carrying of such weapon on such property, and the transporting of such weapon to or from such property.