Re: "You and I" or "you and me" before a "who" clause
Hi Rich
Preliminary point: the verb "be" doesn't take objects: "you and I" is a phrase functioning as a predicative complement.
Let's start by putting the relative who- clause to one side for a moment:
(1) "It's not just you and I/me".
Traditional grammar dictates that a personal pronoun complement of the verb "be" should be in the nominative case, which in your example is "I". But that sounds very stuffy today. In present-day English almost everyone says "me", even though it violates the traditional "rule".
Now for the relative clause:
(2) "You and I/me use this method".
On its own, this clause would require "I" (not "me") since it is part of the subject ("you and I") and subject pronouns are always in the nominative case.
Now, I suspect that is why the writer chose "you and I", since it adheres to the traditional "rule" of using "I" as complement of "be" in the main clause, and complies with the requirement that pronoun subjects be nominative "I", as in as (2).
So the sentence you saw is not wrong at all, but if you want to use the more informal accusative "me" instead of nominative "I" then go ahead, that would be fine too.
