Big supermarkets in Beijing have been instructed by the police to stop selling knives after a Beijing native stabbed four people at a Carrefour shopping center on Monday that left three wounded and one dead. In a similar incident last Wednesday, a young man from Shandong Province stabbed two others to death near a shopping mall in the capital. Both are said to have mental health problems.

Netizens have already ridiculed the move by questioning if knives are really to blame and if such means can help ensure public security.

While they were ridiculing it online, another stabbing case took place in Guangxi Zhuang Autonomous Region Tuesday, in which a knife-wielding man ran into an office in charge of local family planning work and stabbed two to death and injured three others and a lawyer. 

All these incidents happened in public places and threatened public security. At this very sensitive moment when every person's life can be put at risk, the public expects authorities to come up with meaningful solutions. Nonetheless, they seldom feel satisfied with the moves taken by authorities, arguing that China is full of knives already and bans on sales will hardly keep them out of the hands of attackers.

Knife sales and carrying knives in public were banned in Beijing during the 2008 Beijing Olympic Games and the 60th anniversary celebrations of the founding of the People's Republic of China in October 2009, amid paranoia that public order might be disturbed.

The US' experience in regulating guns has taught China some lessons. Americans debate the possibilities of enacting federal legislation to eliminate easy access to guns whenever there is a shooting case like the one in Connecticut last year. A ban on owning a gun in the US, even it benefits the whole society, is impossible to carry out due to the country's adherence to its constitution.

Public opinion, after each extreme case, should criticize violence first and help limit the scope of such cases. Meanwhile, Chinese authorities should take a long-term view when looking into public opinion. They have to reflect on every case and consider issues such as the treatment of the mentally ill, rather than rushing to knee-jerk solutions that do nothing.