People spitting or urinating in public, coming to blows on aircraft with flight attendants and fellow passengers, vandalising cultural relics, and removing shoes on public transport and causing a foul smell.
These are just a few of the litany of revolting behaviours that we have come to tolerate as part of everyday life in China. But imagine the Chinese people doing the same overseas and what that could do to China's soft power.
Such behaviour has largely negated the billions of yuan the government has spent to increase China's soft power. The ongoing effort to boost China's image and win over more of the world's hearts and minds is being unwittingly sabotaged by some of its own citizens.
These symptoms seem to have set off alarm bells in the halls of government, as they should, for the government recently announced that people behaving improperly while touring overseas would be blacklisted.
In a speech in Johannesburg earlier last week, Zhai Leiming, deputy director-general of the Department of Consular Affairs at the Ministry of Foreign Affairs, said that while consular officials can often bail out Chinese businessmen for violating local rules, they cannot repair the damage caused to China's image and prestige.
But I have some sympathy for the nuisance-makers, because most of them are clueless and do not know better.
They merely behave the way they always have at home. Nobody has told them the Chinese equivalent of "When in Rome, do as the Romans do". Nobody has told them that each Chinese national travelling abroad is in essence an unofficial but influential ambassador for China.
Somebody needs to deliver this message urgently.
Last year, the number of outbound Chinese tourists exceeded 100 million for the first time, and the number is expected to double by 2020. This does not include the large number of Chinese working or studying abroad.
This ever-increasing number of Chinese nationals going abroad should be required to take an Internet course on their responsibilities as unofficial ambassadors.
Some countries could even choose to make proof of successful completion as a prerequisite for a visa. And foreign governments could issue all visitors a manual of dos and don'ts, either while issuing a visa or at the point of entry.
Ignorance should no longer be an excuse for unacceptable behaviour and for damaging China's soft power.
To reduce the problems identified by Mr Zhai, the Ministry of Foreign Affairs should take a leadership role abroad in further educating students and Chinese workers at all levels in what is expected of them while living in a foreign land.
In addition, since one of the major criticisms levelled against Chinese students and workers is that they insulate themselves and do not mix with local people, the ministry could help organise gatherings of all stakeholders.
Ignorance breeds contempt. Knowledge fosters understanding and mutual respect.
Since the Chinese people are among the most patriotic in the world, they will act appropriately, but only if reminded of what is appropriate and of how - to a large degree - their behaviour will influence how the world views China. This is a solemn responsibility not to be taken lightly.
The writer is a senior adviser to Tsinghua University and former director and vice-president of ABC Television in New York.