For decades, free-wheeling Hong Kong was reputed as an open Asian economic base, travel hub and place to do business, with a liberal border regime. But, in recent years, the city has taken a stricter, or more discretionary, approach to who it is allowing in – particularly when it comes to political figures. Earlier this month, it appeared to demonstrate a more rigorous immigration policy than mainland China when it turned away a German activist who had arrived after freely travelling around Sichuan and Beijing. As has become typical, the activist – an award-winning journalist and University of…