Well, also the leakage of nearly all information on everyone with a clearance:<p><a href="https://www.businessinsider.com/cia-spies-in-china-may-have-had-cover-blown-from-opm-hack-2015-7" rel="nofollow">https://www.businessinsider.com/cia-spies-in-china-may-have-...</a><p>Edit:
You may have heard that the CIA did not trust OPM, but, once you have a list of everyone with a clearance that <i>is</i> in the OPM databases, you have good grounds for assuming anyone missing, who <i>should</i> have a clearance, is a spy.