Both my wife and sister-in-law have seen them with and without me in the car, just this week a slow huge low flying military plane kept turning with us (me and my wife no sister in law) and followed us right into the school parking lot which it circled as my wife waved to it. When she went into school, with me and the kids staying in the car, she told me to make sure to wave to it if it comes around again. Most of the serious things we say to each other in this area tend to be in joking form especially if the kids are around (my sister in law jokes in this area too).
I think I probably did joke about the house being bugged and I would have actually mostly been really joking and certainly wouldn't be thinking looking for bugs, the context I would say that in would be in the context of if the helicopter, plane, (or blimp) seemed to know when we were leaving the house. I don't want to give the impression we talk/joke about this stuff every day, once a week would be a lot, once a month more the average I would think. The oxygen bottles would be nightly though.
I certainly see stuff in the air lots of times per week, maybe our house and school and frequented stores are just a popular flight plan or our family has mass hypnosis or something, this isn't my area of expertise obviously. I kind of identified with that stalking thread somebody started, I actually posted the stalking by air part from one of the links somebody mentioned.