True story-- I worked as a sysadmin for a number of years, and as such found it useful to carry a knife with me to open boxes-- as receiving equipment was a daily duty for me. My weapon of choice was a CRKT "snap lock" mini knife with a blade no larger than an inch. It was completely inoffensive, but it could open a package quite well and due to the design it was quite safe to keep in your pocket. They don't seem to make this knife anymore-- but be aware it was not the quite large "snap lock" knife CRKT still makes-- this guy about the size of a key.
So, I arrive at Disneyland like any other day. Park in the mega-structure and when I arrive at the security gate, a very respectful gentleman in touristy clothes says to me, "Excuse me sir, can you come over here for a moment?"
He pulls me aside-- he says, "The knife in your pocket. You can't bring that into the park."
I am floored. How could he possibly know about a knife I literally keep on my key ring that doesn't even look like a knife? This is the day I learned that Disney employs security staff to pretend to be park guests.
I said, "Yes, I do have a knife, but I think if I was allowed to show it to you, you might agree that it's not a weapon. If you disagree, then I'll give it to you, so it doesn't enter the park, but don't throw it away because it's a great knife, so consider it a gift."
To his credit, I showed him the knife-- and he said something to the effect of, "That's fine. Have a great day at the park."
To me, this was security done correctly. The guy identified a possible problem (my knife), and was allowed to exercise his own judgement about the situation.