I nearly lost a pocketknife when my suitcase was x-rayed at a Spanish train station.

Our small satchel bags and bodies did not get x-rayed, but the large suitcases did. I forgot I had a pocketknife in there (as it's fine usually for airport security as a check in bag). Somehow, when my suitcase got scanned, they mixed up the order and the person behind me got stopped for having a knife. By that time, I was making a quick getaway to the platform as I didn't want to lose the knife.

I could have just had a knife (and bomb?) in my satchel bag, so was pretty confused by the whole x-ray suitcases only situation.