Social media lit up with surprise, amusement and debate. Some wondered if undercover policing could soon spread to buses or taxis.

The law itself is hardly new. Minibus passengers have been required to buckle up for more than 20 years. What unsettles people is not the law, but the method of enforcement and the sense that small, routine choices are being scrutinised.

The undercover operation seemed to be about prompting immediate compliance. Yet, when minor infractions are policed this way, people may feel they are constantly being watched and trust between the community and authorities risks being eroded.

A routine minibus ride begins to feel like a moral test and small everyday interactions grow tense. Commuters might wonder if the next ride will be a trap. Drivers may feel pressure to monitor passengers as much as the road.