As far as English media is concerned, this is a reasonably accurate and less biased article...
On one level, it is about ring-fencing Hong Kong's identity and resources.
Says Dr Lee: "Localism is very strongly grounded in the differences between Hong Kongers and the 'invading' mainlanders'. Localists hate tolerance; they focus on Hong Kong's identity as a distinctive ethnic group, whose interests are being damaged."
Thus, for instance, rowdy localist protesters heckle mainland day-trippers as "locusts who deprive locals" of goods like formula milk. The entry of mainland immigrants, subject to a daily quota of 150, is also a festering issue. The mainland authorities decide who gets to come in.
Mr Lau underscores the unease, saying: "They are here, not just as tourists but residents, speaking putonghua (Mandarin). And you wonder, am I in Hong Kong or China?"
IT manager S. C. Lam, 40, says he supports localism. "We have lost too much to the Chinese - our economy, social welfare, our water. Traditional ways have not worked, so let's give localism a shot."
More importantly, by becoming a force in the political field, it forces the moderate pan-Democrats to "radicalise", says Mr Yau. "We will not get half (the support), but we can influence the centre."
Beijing's reaction to all this has been expectedly thunderous - it has branded the Mongkok rioters "separatists" - a label Mr Chow says he accepts "with honour".
Asked whether localism will simply cause Beijing to tighten its grip on Hong Kong, such as by ramming through an anti-subversion law, Mr Lau says: "It will happen anyway."
On the old-school pan-Democrats who have said they are Chinese patriots who "love China but hate the CCP", he says: "To us, if you love China, you hate Hong Kong."
Dr Lee says: "The degree of venom towards the pan-Democrats is even higher than towards the pro-Beijing establishment because localists see them as selling out."