Visitors are tracked by face recognition technology from state-owned surveillance equipment manufacturer Hikvision at the Security China 2018 expo in Beijing. Hikvision is one of several firms that have been added to a U.S. trade blacklist. Visitors are tracked by face recognition technology from state-owned surveillance equipment manufacturer Hikvision at the Security China 2018 expo in Beijing. Hikvision is one of several firms that have been added to a U.S. trade blacklist. The Commerce Department has issued a list of 28 state security bureaus and tech companies in China that it says are being used to suppress the country's Uighur Muslims and other ethnic minorities – a move that blocks them from doing business with U.S. firms.