Many concepts sound great in theory but become thorny in practice. One of those concepts is the idea of the "public interest". The term has existed as a principle for good government, in various forms, for thousands of years and it's widely used in law. In a recent blog post, a well-known Ethereum developer implicitly put forward the idea that public blockchains ought to be run in the "public interest". But what does the term mean and is that a standard that ought to be at the heart of Ethereum, or any other public blockchain? It's a concept that's widely used in law. Why not for Ethereum?
The term "public interest" appears in ethical guides, statutes, and administrative law textbooks all over the world. But this simple term hides a complicated reality. Few people agree on what the "public interest" is, how to identfiy it, or how to know when something isn't in the public interest. This is a standard that opens the door to debate, rather than providing a standard in the sense of Ethereum's ERC-20, technical standards, or really anything that programmers would say is a "standard". What lawyers and regulators call a "standard" might surprise people who are not familiar with the thousands of pages of scholarship on various sorts of "standards" in law (e.g. Canadian administrative law).