If you got a bonus or sold a house and deposited the proceeds, the bank would flag the transaction as out of your normal pattern of banking, and you might have to answer questions from federal authorities.
Answers varied a great deal based on the perceived intrusiveness of the question, but one pattern became clear: it was possible to get more people to answer that they had engaged in a given behavior if their own behavior was approached indirectly.
He found his answer by looking up, deciding to extend the ceiling's subtle, white-on-white pattern down two walls to the soffit level on one side and nearly down to the floor on the other.
The case is particularly interesting because the Supreme Court avoided the usual pattern of trying to narrow the question to an interpretation of federal law and instead instructed the parties to answer whether the Constitution bars such suits.