A database containing information about residents in China is responsible for keeping millions of those residents from traveling via trains and planes, according to a new report.

The information comes from a “social credit system” wherein residents are punished for particular offenses, getting themselves blacklisted from certain activities.

Offenses such as public misbehavior or petty theft might be punishable by earning the offender slower internet speeds or a loan denial, for instance. Yet, it is uncertain, according to reports, what offense had been committed to earn such a hefty penalty as being banned from travel.

Some officials believe that the ban might concern people who owe money to the government and the ban is merely an attempt to prevent debtors from escaping their debt.

The controversial list has been collecting information about residents’ misdeeds since 2013 and, as of December 2017, 8.8 million people have been added to the database of debtors.

Unsurprisingly, the “social credit system,” and similarly proposed programs that would score citizens according to their day-to-day financial behaviors, has earned criticism over the years.

According to Anurag Lal who served as a Director of the US National Broadband Task Force for the FCC during the Obama administration: “China’s proposed social score is an absolute reaffirmation of China continuing to push forward to be a complete police state. They take it a step further by becoming not only an establishment of a totalitarian police state that monitors its people but one that completely evades users’ privacy. All forms of activity and interactions, online or otherwise, will be rated, available to view and stored as data.”