A Supreme Court justice’s birthday and Social Security number were exposed on the Internet after a McLean, Va., investment firm employee used an online file-sharing network at his office.

Supreme Court Justice Stephen Breyer’s birthday and Social Security number, and records for about 2,000 other clients of Wagner Resource Group, were stored in the company’s private files. The data breach began late last year and ended shortly after a reader of a blog on washingtonpost.com discovered the information in June on LimeWire.