Why the relationship is fiduciary
Equity has long imposed fiduciary obligations where one party holds discretionary power over another's interests, the other is vulnerable, and ordinary market or contractual protections are unavailable. Government information relationships meet every condition. Citizens must provide information to get a license, pay taxes, enroll a child or receive a benefit. They cannot exit the relationship, bargain for protections, or monitor what happens next. Consent cannot legitimate what the citizen had no real choice to give.
The public trust tradition reinforces the point. Since Illinois Central Railroad v. Illinois (1892), state title to navigable waters has been understood as held in trust for the people. The same stewardship logic extends to the informational commons government holds.
Four duties from four textual sources
The duties are not policy preferences. Each derives from a distinct feature of the Amendment:
Loyalty
Information collected for one purpose may not be repurposed. Loyalty requires purpose-limited sequestration that is incompatible with database integration.
From the particularity requirementCare
Minimization and accuracy. Care favors query-without-collection protocols that prove facts without retaining underlying data.
From the reasonableness standardConfidentiality
Unauthorized access is itself a search. Confidentiality favors individual-held credentials over standing government repositories.
From the search prohibitionTransparency
Individuals, as principals, must be able to know when government, as fiduciary, accesses their information.
From the warrant requirementFrom acts to relationships
Mosaic theory, from Justice Sotomayor's concurrence in United States v. Jones to Carpenter, recognized that aggregation can itself be a constitutional harm. Professor David Gray's work shows why case-by-case aggregation analysis has stalled: thresholds are indeterminate, remedies are incomplete, and doctrine never specifies what compliance requires. All three problems share one root. Existing doctrine evaluates governmental acts. The general-warrant prohibition is about governmental relationships.
The fiduciary framework supplies the relational test. The Otis characteristics give a categorical rather than graduated standard; the four duties give specific architectural mandates; and the question courts must answer is structural, of a kind they are equipped to decide without making policy judgments.
The mapping
| Otis characteristic | Constitutional source | Fiduciary duty | Architectural answer |
|---|---|---|---|
| Discretionary power | Particularity | Loyalty | Purpose sequestration |
| Comprehensive scope | Reasonableness | Care | Minimization; query-without-collection |
| Standing authorization | Search prohibition | Confidentiality | Holder-controlled credentials; renewed authority for exceptional need |
| Accountability evasion | Warrant requirement | Transparency | Access records and notice to the individual |