The government isn’t confirming any loss of PII, but last week it was announced that hackers gained access to several OPM networks, including those that security-cleared professionals use to upload their information. Expect more news to be released over the coming weeks, but the fact that they made the announcement at all means that everyone with a security clearance should be even more skeptical of any unsolicited emails or contacts:
http://news.clearancejobs.com/2014/07/10/us-opm-attack-defeated-systems-breached/