kbf1, whilst I agree in general with all your comments, I am not entirely sure that it is correct that airlines have to comply with the data protection act to record images of passengers.
I notice that at several airports in the UK (Aberdeen and Gatwick for example), as you pass through security your image is recorded on a PC where (presumably) pictures are saved in case of problems later. I am not aware of any disclaimers that these images are being recorded. I would imagine this would have been looked at by lawyers in case of breach of human rights claims etc. Maybe someone in security at these places could comment further.