What's so weird about this? CS literature is not legally binding in any way. Of course a judge would rather quote a previous ruling by fellow judge than a textbook, Wikipedia, or similar sources.
From what I understand, a judge is free to decide matters of fact on his own, which could include from a textbook. Also, it is not clear that matters of fact decided by the Supreme Court are binding to lower courts. Additionally, facts and even meanings of words themselves can change, which makes previous findings of fact no longer applicable. That's actually true in this case as well. "Hash" as used in the context of images generally meant something like an MD5 hash (which itself is now more prone to collisions than before). The "hash" in the Google case appears to be a perceptual hash, which I don't think was as commonly used until recently (I could be wrong here). So whatever findings of fact were made by the Supereme Court about how reliable a hash is is not necessarily relevant to begin with. Looking at this specific case, here is the full quote from United States v. Ackerman:
>How does AOL's screening system work? It relies on hash value matching. A hash value is (usually) a short string of characters generated from a much larger string of data (say, an electronic image) using an algorithm—and calculated in a way that makes it highly unlikely another set of data will produce the same value. Some consider a hash value as a sort of digital fingerprint. See Richard P. Salgado, Fourth Amendment Search and the Power of the Hash, 119 Harv. L. Rev. F. 38, 38-40 (2005). AOL's automated filter works by identifying the hash values of images attached to emails sent through its mail servers.[0]
I don't have access to this issue of Harvard Law Review but looking at the first page, it says:
>Hash algorithms are used to confirm that when a copy of data is made, the original is unaltered and the copy is identical, bit-for-bit.[1]
This is clearly referring to a cryptographic hash like MD5, not a perceptual hash/neural hash as in Google. So the actual source here is not necessarily dealing with the same matters of fact as the source of the quote here (although there could be valid comparisons between them).
All this said, judges feel more confident in citing a Supreme Court case than a textbook because 1. it is easier to understand for them 2. the matter of fact is then already tied to a legal matter, instead of the judge having to make that leap himself and also 3. judges are more likely to read relevant case law to begin with since they will read it to find precedent in matters of law – which are binding to lower courts. This is why a "CS for Judges" could be a useful reference book.
Lastly, I should have looked a bit more closely at the quoted case. This is actually not a supreme court case at all. Gorsuch was nominated in 2017 and this case is from 2016.
