We are all part of the same country

There were more than 8,000 reports of minor infractions such as eating on the MTR last year. My guess is that most were committed by Hongkongers.

For as long as I can remember, there have always been local passengers who clip their nails on the MTR as if they are having a manicure in a salon. I have seen taxi drivers and late-night revellers openly answer the call of nature as if they were in the wilderness rather than a crowded urban environment.

Whatever rudeness or lack of manners may have been displayed by mainland visitors, we ourselves have been guilty of the same and continue to be. Yet we find it OK to pick on a mainland girl snacking on instant noodles on the MTR or mass-circulate a video clip of a mainland child relieving himself with help from his mother and aunt as if it is proof of mainlanders' indecency and uncivilised nature.

The full-page advert about locusts - read mainlanders - invading Hong Kong, which was paid for by a group of online local bigots, is a national disgrace. It appeared on Wednesday in a mass-circulation paper that fancies itself as the lone voice of democracy. If this is what being the voice of the people means, I want no part of it. The ad's message, with its air of superiority and self-righteousness, is revolting.

More sombre pundits find the cross-border culture war to be, at its roots, a clash of fundamental values.

Thus Alice Poon, author of Land and the Ruling Class in Hong Kong, writes: 'On a deeper level, the unbridgeable gap seems to be between (Hongkongers') acceptance and (most mainlanders') rejection of or aversion to universal values like rule of law, democracy, equality and liberty.'

The people who ran the locust ad do not strike me as defenders of the rule of law, equality and liberty. Critics like Poon and other old-style democrats can fantasise about Hong Kong being an island shielded from the mainland. Without citing more complex factors, geography alone precludes that.