"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."