This chapter examines a series of PSI investigations into abusive tax shelters, especially tax shelters used by wealthy individuals and those featuring offshore gimmicks. The first inquiry exposes how accounting firms like KPMG mass-marketed tax shelters in exchange for lucrative fees. The second features a case study of the Wyly brothers who hid hundreds of millions of dollars in a network of 58 offshore corporations and trusts. The third recounts how two billionaires used an offshore tax shelter called the POINT Strategy to dodge capital gains taxes. The chapter shows how the hearings helped spur criminal and civil enforcement actions against the tax shelter promoters, and led to the accounting industry’s largely abandoning the U.S. tax shelter business.