I work for a shipping company that's on airport turf, so we have airport security standards to follow every time we enter and exit the building. The last year or so I've only been scheduled a few times a week, but I take the occasional on-call shift. Every time I get the call to hurry in and help out, I've either got my Glock or a few knives on me (Kershaw as a knife-knife, Leatherman for general nonsense).
Last time I got called in, I forgot, they didn't notice, and everyone involved remained cheerfully oblivious to the knives in my pockets. One of the downsides to not working overnights routinely any more is that I tend to be a little scatter-brained when I do get called in for work. When I reached into my pocket for something mid-shift and realized I still had knives on me, I got a little worried about getting past security on my way out. Took a chance, explained to them what happened, and they just waved me through.
Overall, the whole thing wasn't a big confidence booster in their ability to keep weapons out.