In today’s Impromptus, I write about Gao Zhisheng, a Chinese prisoner of conscience. Horrible, horrible things have happened to him in the past; horrible things are almost certainly happening to him now — if he is still alive. On February 4, he was “disappeared.” His family has escaped to the United States.

A reader wrote to tell me of something called — yes — www.persecution.com: a site that will lead you to www.prisoneralert.com: where important facts about Gao, and others, are available. These include steps that individual citizens — all of us — can take. Gao is an amazingly brave man. Indeed, he exhibits a bravery, and a determination, that I can scarcely fathom.

Of course, I have said that about many men and women, many of them from Cuba and China. Americans have a role to play here: if only they will play it.