Michael Kennedy writes on the criticism page:
Popper’s falsifibility criterion is only a necessary condition for scientific status. If by demarcation criterion we mean a frontier with scientific statements on one side of the line and non-science on the other then falsifibility does not work. For any old prophesy such as the world will end tomorrow or I will win a gold medal at Rio will be scientific. What falsifiability does is distinguish the empirical from the non-empirical. And that is well worth doing. Popper did use term “demarcation” but he was not as clear as he might have been, and I am not sure of quite where he stood. Did he perhaps confuse himself, or was he thinking of less strict meaning of the term “demarcation”?