Foreign judges at the top of Hong Kong's judiciary resign

Three foreign judges in Hong Kong's top court have have resigned. One to spend more time with her family, and the other two because they believe Hong Kong's judiciary can no longer operate independently. The problem, they say, is China's national security law it passed in Hong Kong which allows the Chinese mainland government to intervene in cases of "secession" and "subversion," among other violations. In practice, it's been used to crack down on free speech and dissent, according to human rights experts. The World's host Carol Hills talks with Tom Grundy, editor-in-chief of the Hong Kong Free Press, about the judges who have resigned.