Ask and you shall receive.
Alidar Jarok wrote:
Interestingly, it is not uncommon to capitalize you formal in Italian (Lei). I think the reason is that "lei" is also she, so it is done to distinguish the two.
I don't think that confusion with "lei" (she) is the main reason (even if it's a possibility). In fact, in formal letters also Voi (plural you) and Vostro/a/i/e (plural your) are capitalized.
Nobody would ever think of capitalize "io" (I). It would be seen as the epitome of narcissism.