The Charenton asylum by Jacques Gilbert, one of the paradigmatic Neoclassical buildings of the 19th century, was built on the principle of categorizing patients by sex and by twelve specific kinds of illness. Its layout, like those the asylums in Rouen and Marseilles, followed a plan specified by the theoretician Esquirol: residential quarters in two arms, arranged in a U shape around a central court and anchored by the common facilities and the administration building. (Architecture in France 1800-1900,Betrand Lemoine, Abrams 1998, p64)
The human mind loves categorizing, and cultures love to turn categories into concrete structures. Categories are useful tools for thought, but they are means, not ends; in other words, they're the scaffolding, not the building.
When the scaffolding becomes more important than the building, the results range from the obscene to the mundane. All the bad -isms like racism, sexism and ageism are the result of categories that are used to discriminate between people (in the sense of discerning a difference) becoming reified into self-evident truths which are used to discriminate (in the sense of treating unfairly).
The layer model for regulation of the internet is a current mundane example. (See, for example, Werbach, Whitt.) The OSI stack is a good way to analyze networks, but in and of itself it is not a basis for regulation. The way a given technology is built -- or, more precisely, explained -- at a given moment does not generate the basis for regulation in a straightforward way. It's worth noting that there is no one agreed-upon model; there are many ways to count and name the Internet's layers.
The material force of categories is inescapable and immediate, as Bowker and Star describe at length in Sorting Things Out: classification and its consequences. As they say: "Each standard and category valorizes some point of view and silences another. This is not inherently a bad thing -- indeed it is inescable. But it is an ethical choice, and as such it is dangerous -- not bad, but dangerous"