found a couple of "hints" at the what the IRS fears:


http://www.irs.gov/irm/part35/ch18s21.html#d0e637529


35.18.23.3& (04-08-1992)
Fourth Amendment Claims


1. <SPAN class=italic>Scope.</SPAN> The fourth amendment to the Constitution protects against unreasonable searches and seizures, and further provides that search warrants must not be issued absent probable cause, and if issued must be specific. In this regard, <U>taxpayers have had some success in defeating assessments based on illegally seized evidence, and compelling the return of property unlawfully seized pursuant to a tax assessment.</U>


2. <SPAN class=italic>Warrantless Seizure of Property.</SPAN>


In <SPAN class=italic>G.M. Leasing Corp. v. United States,</SPAN> 429 U.S. 338 (1977), pursuant to an assessment, the Service seized automobiles belonging to the taxpayer located on public streets and books and records from its office without a warrant. The Supreme Court held that a warrant was not necessary for the seizure of property from public streets but that the taxpayer's office was a constitutionally protected area requiring a warrant. <U>The Court rejected the Government's argument that warrantless intrusions into privacy in furtherance of enforcement of the tax laws constituted an exception to the fourth amendment.</U>


4. <SPAN class=italic>Right of Privacy.</SPAN> Taxpayers have unsuccessfully asserted that their private papers including their tax records were protected from an Internal Revenue Service summons by the fourth amendment. <U>The Supreme Court has held that the only proper objection to the forced production of documents would be under the fifth amendment, and not the fourth amendment.</U> <SPAN class=italic>Fisher v. United States,</SPAN> 425 U.S. 391 (1967).


Randy