I know a woman who worked at a company with high security. There were detectors (similar to those at the airport I suspect) at all the entrances and I heard her tell this story.
She and several co-workers were entering the building, going thru the detectors and her friends triggered the device, as usual. When she went thru, however, nothing happened. Somehow her energy field wasn't registering on the device. I think she tried several times with similar results.
I don't know if she's an abductee, but she has a high level of interest in ETs.