I once read a quote from a futurist that many distinctions that we currently take forcar granted will be not be valid in the future. Things that seem as different as day and night will be indistinguishable. Day and night, for example. The proliferation of night vision and other sensor technologies will cause future generations to have radically different views about the level of privacy traditionally offered by the cloak of night. Another distinction that is already blurred is the one between manned and unmanned vehicles.  Read full article here.