Facebook Staff Fret Over China’s Ads Portraying Happy Muslims in Xinjiang Workers express concerns internally about advertisements and content by Beijing promoting message that mostly Muslim ethnic minorities in the region are thriving HONG KONG— Facebook Inc. is blocked in China, but Beijing is a big user of the platform to spread its political views to hundreds of millions of people overseas, sometimes via advertisements. Now, some Facebook staff are raising concerns on internal message boards and in other employee discussions that the company is being used as a conduit for state propaganda, highlighting sponsored posts from Chinese organizations that...