https://marginalia.penrose.institute/ Notes in the margins. Observations, arguments, and asides from the work of building a discipline. en-us https://marginalia.penrose.institute/osint-in-public-law/ https://marginalia.penrose.institute/osint-in-public-law/ Tue, 11 Nov 2025 00:00:00 +0000 info@penrose.institute (Jeffrey Mader) The definition of OSINT in U.S. Code is a congressional finding, not a binding mandate. Services retain the authority to define the discipline to meet their own operational and policy needs. https://marginalia.penrose.institute/adtech/ https://marginalia.penrose.institute/adtech/ Sun, 02 Nov 2025 00:00:00 +0000 info@penrose.institute (Jeffrey Mader) Commercially available location data is probabilistic telemetry, not GPS gospel. Centroid bias, time-distance jumps, and replay are the three artifacts most likely to lead an analyst astray. https://marginalia.penrose.institute/osint-hyphen/ https://marginalia.penrose.institute/osint-hyphen/ Thu, 03 Jul 2025 00:00:00 +0000 info@penrose.institute (Jeffrey Mader) Why "Open Source Intelligence" should never be hyphenated. The hyphen describes a kind of product. Without it, the phrase names a profession, and in bureaucracies language signals legitimacy. https://marginalia.penrose.institute/corporate-fraud/ https://marginalia.penrose.institute/corporate-fraud/ Sun, 12 Mar 2023 00:00:00 +0000 info@penrose.institute (Jeffrey Mader) Over the next 45 minutes, you will learn the high level concepts, terms, and resources related to open-source investigations of corporate fraud and money laundering. Enjoy! https://marginalia.penrose.institute/seago-piraeus/ https://marginalia.penrose.institute/seago-piraeus/ Fri, 19 Aug 2022 00:00:00 +0000 info@penrose.institute (Jameson Matinho) A container flagged for radioactivity at Mombasa, and a walk-through of the open sources that identify the vessel, the container, the consignor and the intended recipient — IMO numbers, container registers, GSTIN records and AIS. https://marginalia.penrose.institute/osint-yacht/ https://marginalia.penrose.institute/osint-yacht/ Wed, 16 Mar 2022 00:00:00 +0000 info@penrose.institute (Jeffrey Mader) When a sanctioned oligarch's yacht switches off its AIS beacon, it does not vanish. A walkthrough of MarineTraffic, yacht-watchers, geolocated social media, and the tenders that give the ship away.