We have been having a problem with our diaper bag setting off the detectors for a few months now. Prior to that, it never got flagged. I asked what could possibly be setting it off, and the only thing the security guard could pinpoint were the cans of sunblock and bug spray that were stuffed together in a side pocket. There's nothing electronic or metal in that bag. Next trip, we're going to put those cans in the stroller and see if the guest is correct!