China¡¯s sweeping national security law is forcing technology firms to reconsider their presence in Hong Kong, and the nimblest among them ¡ª the city¡¯s startups ¡ª are already moving data and people out or are devising plans to do so.

Beijing¡¯s polarizing law, which took effect this month, upended Hong Kong¡¯s tech scene just as it seemed on a path to becoming a regional hub.

Entrepreneurs now face a wave of concern from overseas clients and suppliers about the implications of running data and internet services under the law¡¯s new regime of vastly expanded online policing powers. Many are making contingency plans and restructuring their operations away from Hong Kong.