The U.S. government is the “biggest buyer in a burgeoning gray market where hackers and security firms sell tools for breaking into computers,” Reuters reports. The report accuses the Chinese government and military of targeting U.K. government and defense networks. China’s reaction: The accusations are “groundless” and “hype” The starting rate for a zero-day is around $50,000, some buyers said, with the price depending on how widely installed the targeted software is and how long it’s expected to remain exclusive.”]