Details of the law emerges:
Beijing has given mainland China authorities broad powers to hear ‘complicated’ cases and operate freely and independently in Hong Kong, with life imprisonment for the most serious offences.
www.scmp.com
Interestingly Article 38 states:
Article 38
This Law shall apply to offences under this Law committed against the Hong Kong Special Administrative Region from outside the Region by a person who is not a permanent resident of the Region.
So it means it is applicable to everyone outside HK who are not even HK permanent residents. I.e.
Everyone on Earth.