Four Chinese journalists were arrested this year for allegedly blackmailing companies and individuals, according to media regulators.

The journalists worked with local offices of four national newspapers based in Beijing. They were accused of extorting money by threatening negative publicity or deceitfully promising favourable reporting.

The cases bring home the importance of a self-imposed press code to guide our behaviour, a badly needed element of professionalism in an increasingly competitive media environment.

The domestic media has been dubbed a mixed label of guardian of social justice - deservedly called "king makers" - and devil of social scourges trapped in corruption, plagiarism, biased reporting or sheer concoction.

We've seen conscientious journalists writing for the interest of the general public become victims of social injustice and corruption. Some have even sacrificed their lives for truthful reporting.

Those are journalists of principle and serve as examples for all professional journalists.

But no rarer are journalists who use their occupation as a tool for personal gains, not for promoting the well-being of society.

In some places, journalists who attend press conferences are given cash amounts and material gifts for favourable coverage. And reporters are often accused of resorting to subterfuge skills. Worse, some have gone so far as to violate the law, as shown in the extortion crime of the four arrested journalists.

Such irregularities sap the public confidence won by our honourable colleagues who adhere to professional ethics. The unethical ones make it difficult for honest journalists to carry out their due duty.

Facing increasing discontent from the public, the media should first conduct serious soul-searching and impose stricter self-discipline instead of finding fault with others.

No excuses should be made to explain away regrettable behaviour committed by the industry's black sheep.

Competition is no excuse, either.

The Chinese media industry has developed dramatically and quickly, which brings along cut-throat competition. All reporters face the pressure of finding exclusive news. And some even are assigned to the task of finding advertising and sponsorship.

Journalists should act in accordance with rules and the law. Otherwise, they damage not only their personal fame, but the sector's reputation as a whole, even if we do not mention the big issue of public interest.

Professional integrity is the cornerstone of journalistic credibility.

The media must decide whether to let things be or insist its journalists better abide by the press code.