One of Hong Kong’s most reputable sources for public opinion data is limiting its survey scope, including on sensitive topics such as the Tiananmen crackdown. The change comes on the heels of a risk evaluation done by the Hong Kong government, and will likely muffle access to information showing changes in public sentiment toward the city. Hong Kong Public Opinion Research Institute announced Tuesday it tentatively decided to cancel about one-fourth of its regular survey questions. About one-third of the remaining questions would only be used internally. Critics say that’s a great loss to Hong Kong, which was once famed for its freedom of expression.