Hong Kong students and university faculty previously accustomed to academic freedom must now tread carefully to avoid retribution for what they teach, research and publish – and even with whom they associate – according to a new Human Rights Watch (HRW) report on academic freedom in the city since the 2020 National Security Law was imposed by Beijing. The law prohibits “secession, subversion, terrorism and collusion with foreign forces” to endanger national security but definitions of what constitutes such offences are vague.