I don’t think those are the precise words, but there was a SCOTUS decision I read I believe from this term, that referenced an older opinion. The gist of the statement said that the court wouldn’t allow vague rules that could be read expansively and rely on the government using its power justly, that in interpreting a law the courts needed to look at the ways a law could be misused, not just how the people acting promised they would act.
I believe the reference was to an older opinion by Roberts, but I can’t recall the right key terms to find it. Any idea what this was?
Were the “vague” rules you’re describing arising from statute or a contract? What you’re describing sounds similar to US v Drew, where SCOTUS ruled that prosecuting someone under computer unauthorized access statutes (the CFAA) for violating a website’s terms of service is invalid because a private TOS contract is too vaguely written to be interpreted, in essence, as a law.
I suspect the term that you are looking for is “void for vagueness.” You didn’t give me enough to trigger a memory of the specific opinion you want but I hope I can at least start you in the right direction.
It’s not void for vagueness - that one I know. There was a recent case where the court wrote something to the effect of, we can’t have laws or administrative rules and expect prosecutors to act magnanimously - so if the law allows for a bad outcome because of its vague wording, that we can’t simply trust the government will not exercise its power unwisely.