The legislation bans secession, subversion, terrorism and collusion with foreign forces. The first sight of it for Hongkongers was the moment that it came into effect on Tuesday at 11pm, ahead of the annual 1 July protest march, which itself had been declared illegal.
In one fell swoop, the new law pushed through many of the changes most feared by Hongkongers, by giving mainland legal bodies jurisdiction over some cases inside the territory, allowing the mainland security services to establish offices in the territory, permitting rendition to China and implementing national security education in local schools.