Never had a problem with the KYSS in airport security, even internationally. I use it as my personal item (throw my purse in there). I actually lock it though going through some lines with machine. Don't want anything magically disappearing when the lines are long, lots of bags and people.
However I don't really carry anything in there that would set off scanner. My carry on has my camera bag, so times that sets off a check.
Note to everyone, had a TSA agent flag one carry on (wheeled bag) after cruise for a ship model. Sat there for 20 mins while agent took it out and unwrapped .... Only to find the Wonder. DH stayed with bag (surprise for DS) then the same thing with a golden Mickey statue, also a surprise. Tried everything I could to distract DS while she painfully slowly unwrapped that too.
