Thanks to both jtturner and JCarter for responding to this issue. I hope jt's story has a happy ending.
Since this happened to me, I've been looking into this whole question of identity theft, and it's become more and more obvious to me that it's really important to take these security breaches seriously. Javelin Strategy & Research, which conducts the country's largest identity-fraud survey each year, reports that "individuals who are notified of a breach have dramatically increased risk of fraud with each passing year." Yikes! That's no good.
Here's the link: https://www.javelinstrategy.com/blog/2012/03/30/do-data-breaches-lead-to-fraud-its-hard-to-argue-with-the-data-on-this-one/
Best of luck,