A 4-YEAR-OLD without a boarding pass was found on a Beijing-Shanghai flight before the plane took off on Sunday, causing a delay of nearly five hours. The child's parents did not buy her a ticket, because they "thought" teenagers shorter than 1.2 meters could travel for free. Beijing News commented on Tuesday:

The incident at Beijing Capital International Airport has again aroused concerns about misbehaving passengers and the potential security risks they represent.

Incidents such as this, and that of the 80-year-old passenger who recently threw a handful of coins at one of the engines for "good luck", highlight some people's lack of safety awareness, which could lead to costly consequences.

In the case of the child who was able to get on a plane without a boarding pass, the airport security checks should be blamed for failing to stop a ticket-less passenger. But her parents, who went to great lengths so their daughter could avoid the checks, need to pay the price for their misdeed.

Free-riders on buses and trains are nothing new, and some people might be tempted to try and get a free ride on an airplane if they thought they could get away with it.

Those violating security rules and many other public codes of conduct should be held accountable. That said, verbal warnings may not be enough to keep at bay such "troublemakers". They should receive penalties that deter others from disobeying the rules.

Airline companies are obligated to compensate other customers if a delay is caused by their fellow passengers, according to the Contract Law. Those passengers who cause delays through risky or absurd behavior should have to pay the costs as a reminder to others that the rules are there for a reason.