Mark Milton and Professor Walker discuss the constitutionality of IRS “due diligence visits” to tax return preparer offices during tax season. The purported purpose is to determine whether the preparers are exercising “due diligence” on returns claiming the earned income credit, but Mark argues the visits infringe on constitutional rights (4A, 5A, and 6A), and are unnecessary given the other investigative tools available to the IRS, such as issuing summonses.