Thanks for the replies. You both more or less confirmed what I suspected, but I am still amazed at the large number of videos on YouTube, clearly taken through the window of the passenger cabin, in all phases of flight.
I appreciate airlines set their own policies, but there are even more examples of videos taken from the flight deck, so I cannot understand the stance of cameras interfering with flight instrumentation. Obviously the videos from the flight deck are sanctioned by the airlines concerned, and the airlines doing so include the big world wide carriers..
So where is the problem? If you look at the publicly viewable videos it is fairly obvious that the camera(s) used are not secretly hidden, as the stability of most shows that they must be clamped to some sort of suction device.
As an infrequent flyer, I enjoy the view out of the window (cloud cover permitting) and merely want to record some of the interesting sights I see.