(In this instance, legally safe ones)
I went to a lecture today entitled
Relationship between the PRC Constitution,
the Hong Kong Basic Law,
“One Country, Two Systems” and
the Hong Kong National Security Law
and I wanted to share the slides, 'cos it was a good talk for anyone interested in how the National Security Law actually works, and it also introduces the basics of how the Central Government and Hong Kong regional government function (the lecture was for English speaking teachers in Hong Kong, so a lot of them were clueless). And a lot of useful facts to debunk accusations that HK's autonomy is fake.
The files are in pdf format.
Also the speaker was Miriam Lau, who used to be a member of the National People's Congress. First time I got to meet someone from China's highest organ of state power (but she's not communist though; she's a Beijing loyalist conservative).
edit: post is here