The framework treats a system as critical ecological infrastructure once several triggers hold together: a large share of society depends on it, its failure would disrupt essential services, no practical substitute exists, many downstream systems require it, and a refusal of access would materially harm participation. The classification matters because ownership law was developed for products, not for privately controlled cognitive infrastructure on which whole societies may come to depend.
Its governing principle is that ecological importance creates obligations that ordinary ownership does not erase. Once a system becomes infrastructure for the field, its owner no longer stands where an ordinary private seller stands, and unlimited jurisdiction over it stops being legitimate — the larger the dependency, the larger the stewardship obligation, and the stronger the requirement for plural access, contestability, and real exit. This is the limit-jurisdiction end of the response to ownership concentration, and it is deliberately indifferent to whether the owner is private or public: what triggers the obligations is indispensability, not tax status.