Four of the five Hong Kong booksellers who went missing last year have "voluntarily" confessed on Chinese TV that they'd been detained last October in mainland China for running an "illegal business" of "banned books," Reuters reported on Sunday.
The Causeway Bay Bookstore, where all five booksellers worked, primarily sold political gossip books. Phoenix Television says that the shop crossed the line by mailing "banned" books to mainland readers.
Despite the TV report using the word "banned," China hasn't actively prohibited any specific books — the country has not gone through any legal process to justify the banning of any book or published any kind of list of banned books.
According to China's Customs Bureau, those publications "harmful" to China's politics, economics, culture, or morality are prohibited from entering the country.