ProPublica is a nonprofit newsroom that investigates abuses of power. Sign up to receive our biggest stories as soon as they’re published. It was a multibillion-dollar strike, so stealthy and precise that the only visible sign was a notice that suddenly vanished from a government website. In August 2017, a federal agency with sweeping powers over the health care industry posted a notice informing insurance companies that they weren’t allowed to charge physicians a fee when the companies paid the...