One of their primary targets was the IRS, with which Scientology was engaged in a bitter battle over tax exemptions. As part of a wider strategy codenamed Operation Snow White, the GO succeeded in infiltrating a Scientologist into the IRS to steal files about the government's litigation strategy against Scientology. Mary Sue was closely involved in the strategy; a letter written by her, approving the thefts, was later used in evidence against her. In March 1976, she approved an illegal plan to obtain "non-FOI data" from the government, meaning classified documents not available through the Freedom of Information Act. The GO's agent in the IRS, Michael Meisner, was ordered to obtain all files concerning L. Ron and Mary Sue Hubbard from the IRS Office of International Operations, which he succeeded in infiltrating.