According to court documents , Guillaume worked for a company that performed medical laboratory tests where he had access to medical records with names , dates of birth , and Social Security numbers ( personal identity information or PII ) of individuals in the course of his employment with that company . During the conspiracy , Guillaume stole PII from the company and sold five thousand individuals PII to Ponds . Guillaume knew that Ponds would use the PII for the filing of fraudulent and unauthorized tax returns . Ponds caused other individuals to file false and fraudulent tax returns with the Internal Revenue Service ( IRS ) seeking refunds using the PII provided by Guillaume . By then , the group had access to the first 24.5 million accounts , in chronological order of creation . ;