The New York Times on the very real possibility the OPM attack may have allowed the attackers – allegedly China – to obtain the names of Chinese personnel with ties to the US government by cross-checking the SF-86 data they exfiltrated:

Investigators say that the Chinese hackers who attacked the databases of the Office of Personnel Management may have obtained the names of Chinese relatives, friends and frequent associates of American diplomats and other government officials, information that Beijing could use for blackmail or retaliation.

Federal employees who handle national security information are required to list some or all of their foreign contacts, depending on the agency, to receive high-level clearances. Investigators say that the hackers obtained many of the lists, and they are trying to determine how many of those thousands of names were compromised.

In classified briefings to members of Congress in recent days, intelligence officials have described what appears to be a systematic Chinese effort to build databases that explain the inner workings of the United States government. The information includes friends and relatives, around the world, of diplomats, of White House officials and of officials from government agencies, like nuclear experts and trade negotiators.

“They are pumping this through their databases just as the N.S.A. pumps telephone data through their databases,” said James Lewis, a cyberexpert at the Center for Strategic and International Studies. “It gives the Chinese the ability to exploit who is listed as a foreign contact. And if you are a Chinese person who didn’t report your contacts or relationships with an American, you may have a problem.”