That’s why I find it so funny the are waving US flags, along with Pepe the Frog flags. If they tried throwing Molotov cocktails at US cops, the outcome would be very different.
Pepe the Frog does not have the far-/alt-right connection here that he does in the US and elsewhere. The image is simply used as something cute and funny.
Molotovs... well, very few if any have actually been thrown at the police, rather than at barriers or police stations. There has been a ratcheting of violence, driven almost entirely by the police, and ultimately the government's complete failure to respond or act to massive peaceful protests. I am strongly in favour of the protests, and while I can't say I agree with every action of the frontliners, I cannot condemn then - I know what they're fighting for and against.
(Some) US cops are terrible. (Many) Hong Kong cops are brutal and out of control. I don't wish either force on either population.
Gibson has since been indicted for felony riot which can carry a term of up 5 years, incidentally.