Ethan Gutmann, a fellow at the conservative think-tank Foundation for Defense of Democracies and China watcher, concluded that organ harvesting from prisoners of conscience became prevalent when members of the Uyghur ethnic group were targeted in security crackdowns and "strike hard campaigns" during the 1990s. According to Gutmann, organ harvesting from Uyghur prisoners dropped off by 1999 with members of the Falun Gong religious group overtaking the Uyghurs as a source or organs.[158][159][160]