Gouled was involved in a conspiracy to commit mail fraud against the United States. At the direction of the government, Cohen, a business acquaintance of Gouled, pretended to make a friendly visit to Gouled at his office. When Gouled stepped out, Cohen seized and carried away several documents that were later introduced against Gouled at trial.
Whether an agent of a government has to comply with the Fourth Amendment?
Yes. The Fourth Amendment requires compliance by government agents.
The secret taking, without force, from the premises of anyone by a representative of any branch of the Federal government is a search and seizure. It is immaterial that entrance to the premises was obtained by stealth or through social acquaintance, or in the guise of a business call.
255 U.S. 298, 41 S. Ct. 261 (1921)