Those operatives, in turn, secretly employed the details to rally firearm owners to elect pro-gun politicians running for Congress and the White House, a ProPublica investigation has found.

The clandestine sharing of gun buyers’ identities — without their knowledge and consent — marked a significant departure for an industry that has long prided itself on thwarting efforts to track who owns firearms in America.

At least 10 gun industry businesses, including Glock, Smith & Wesson, Remington, Marlin and Mossberg, handed over names, addresses and other private data to the gun industry’s chief lobbying group, the National Shooting Sports Foundation. The NSSF then entered the gun owners’ details into what would become a massive database.