The Securities and Exchange Commission arrived in my professional world not with a warrant but with a letter. A Wells Notice, technically — the agency’s notification that staff intended to recommend enforcement action to the commission. The subject wasn’t me. I was called in as an expert witness in a fiduciary dispute. But that engagement introduced me to what federal financial surveillance looks like from inside the process: document demands reaching back years, trading records, client communications, all obtained not through a judge but through an administrative subpoena.

The Fourth Amendment says the government can’t conduct unreasonable searches and seizures without a warrant supported by probable cause. I knew that. What I understood more fully after that engagement is what the Fourth Amendment doesn’t say: it doesn’t say the government can’t compel your bank, your broker, or your custodian to hand over your financial records without telling you. That authority rests on a doctrine the Supreme Court developed in the 1970s, and it has shaped the relationship between American citizens and their financial institutions in ways that most people who open brokerage accounts never consider.