We’ve gone through the paucity of evidence related to who was behind the OPM hack before. FBI officials suggested they were looking into a number of situations, including the possibility of “state actors,” which led some media outlets to say they might be looking at China, which led Congressmen to say they heard on the TV that China did it, which led the media outlets to cite the Congressmen as proof China did it.
The evidence hasn’t been there though, and officials are saying it never will be. Today, US officials announced in the Washington Post that even though they’re pretty sure China did it (likely because they heard that on the TV), they aren’t going to publicly accuse them of doing so, apparently unclear on whether the Washington Post counts as public or not.
Officials are also saying “privately” (again, in a huge circulation newspaper) that they might impose sanctions on China for the hack, but not publicly say the sanctions are because of the hack, even though they literally just did say that.
The OPM hacks breached the data of some 20 million US government employees past and present, and despite the speculation that China did it for some national security purpose, those people have also been advised of the risk of identity theft for credit scams and whatnot in case this was actually a private group that hacked them for all the valuable information.