"The social media giant has rolled out a new prayer request feature, a tool embraced by some religious leaders as a cutting-edge way to engage the faithful online. Others are eyeing it warily as they weigh its usefulness against the privacy and security concerns they have with Facebook".--Under its data policy, Facebook uses the information it gathers in a variety of ways, including to personalize advertisements. But the company says advertisers are not able to use a person's prayer posts to target ads.