The Chinese government blocked 17.5 million would-be plane passengers from buying tickets last year as a punishment for offences including the failure to pay fines, it emerged.
Some 5.5 million people were also barred from travelling by train under a controversial “social credit” system which the ruling Communist Party claims will improve public behaviour.
The penalties are part of efforts by president Xi Jinping‘s government to use data-processing and other technology to tighten control on society.
Human rights activists warn the system is too rigid and may lead to people being unfairly blacklisted without their knowledge, while US vice-president Mike Pence last year denounced it as “an Orwellian system premised on controlling virtually every facet of human life”.
Authorities have experimented with social credit in parts of China since 2014. Points are deducted for breaking the law, but also, in some areas, for offences as minor as walking a dog without a lead.