The authors follow a line of inquiry into whether signs of adherence to Shariah (Islamic law) within the mosque -- for example, sex-segregated prayer, regimented prayer lines, bearded imams -- indicate the presence of inflammatory material. Take sex-segregated prayer. They found that 95 percent of the mosques where men and women pray separately contain violent literature. At the same time, however, so do 74 percent of the mosques where men and women pray together. Similarly, 94 percent of the imams presiding over sex-segregated congregations recommend the study of violence-positive material; but so do 80 percent of the imams leading co-ed services. So, yes, Shariah-adherence is a sure-fire indicator, but it's not the only indicator. No wonder the authors consider the conclusions to be drawn from their survey as "dismal at best." But what will those conclusions be? What should they be? I conclude, just for starters, that there is an urgent need to halt Islamic immigration to ensure that the demographic for more such mosques doesn't grow. But having dug up the hard data on the textual embrace of Islam-inspired violence within organized Islam in America, the authors almost seem content to throw it all away: "This survey suggests that, first and foremost, Muslim community leaders must take a more active role in educating their own faith community about the dangers associated with providing a safe haven for violent literature and its promotion." The data may be new, but this is the same old mistake we've made since 9/11: outsourcing our response to the ideological threat posed by Islam to "Muslim community leaders" -- and usually linked to the Muslim Brotherhood. This isn't an internal Islamic problem. These alarming data on the promotion of violence within Islam in American mosques are for the wider, still non-Islamic society to address, and before it's too late.