Remember when President Donald Trump tried to ban TikTok? He called attention to the risk that American users’ data could fall into the hands of Chinese authorities who have ties to the app’s owners. A judge blocked the ban, but even if he hadn’t, experts say so much of our personal information is available to buy from run-of-the-mill data brokers. That includes information on Americans serving in the military, which can have big consequences for national security. Marketplace’s Lily Jamali spoke to Justin Sherman, senior fellow at Duke University’s Sanford School of Public Policy, about a new study he led in which his team tried buying just that kind of data.