26 U.S.C. § 7601 : US Code - Section 7601: Canvass of districts for taxable persons and objects

Search 26 U.S.C. § 7601 : US Code - Section 7601: Canvass of districts for taxable persons and objects

(a) General rule
The Secretary shall, to the extent he deems it practicable, cause
officers or employees of the Treasury Department to proceed, from
time to time, through each internal revenue district and inquire
after and concerning all persons therein who may be liable to pay
any internal revenue tax, and all persons owning or having the care
and management of any objects with respect to which any tax is
imposed.
(b) Penalties
For penalties applicable to forcible obstruction or hindrance
of Treasury officers or employees in the performance of their
duties, see section 7212.