United Nations human rights experts made global headlines in a session that concluded Monday when they said they believe China is holding 1 million members of a Muslim minority group in secret prison camps.

Its a scale of tyranny thats hard to imagine a sprawling system of detentions for political re-education and a growing surveillance network outside the camps, ostensibly the only possible response to the risk of terrorism. But despite the Chinese governments vast, often brutal attempts to control what the world knows about its repression, the U.N. announcement is also proof that Chinese citizens, journalists and advocacy groups are succeeding in long-shot efforts to get the truth out.

The Uighurs, the ethnic group targeted by Chinas ruling Communist Party, have realized that it doesnt help to be quiet, said Zubayra Shamseden, the Chinese outreach coordinator at the Uyghur Human Rights Project. Just days ago, she heard from one more Uighur willing to volunteer his familys story for the first time because his brother, a Communist Party loyalist with whom he had long squabbled over politics, had disappeared.

China has been wary of the 10 million Muslim, predominantly Uighur residents of its northwestern Xinjiang province for decades. Beijing ramped up security checks and forced integration with the countrys Han Chinese majority amid global fears following the 9/11 attacks; it argues that without those measures the Uighurs and related communities would join Islamist extremists or separatist groups that have killed hundreds.