Don't do it, or you will feel sorry later.
If the place you're trying to sneak in has security, then you shouldn't worry too much about defending yourself with a weapon. If you want to have a self defense weapon on you all the time, you better off choosing something not lethal, like a kubotan (can make one yourself). If you want to scare off people just by angry stance, go to the gym and work out.
Cold steel night shade knives are bad letter openers and mainly designed for stabbing (killing). If you want one to play with at home, get it, but think 10 times before deciding to carry it. If you get caught with one, you will have a hell of a time explaining the reason for having it on you, even if you didn't really do anything "bad". And if you end up doing something "bad", that plastic thing will most certainly get you in much deeper pile of doodoo.
If you need ability to cut things at any time in any place, get a keychain knife. It is much more useful then buckle knife, not threatening and easy to carry through security.
As other have said, carry a pen/pencil (not necessarily tactical).
For about $10 you can get a truly useful tool that will help you in many ways and won't get you in trouble.