A form submit hack to an open document is not illegal nor in my opinion, unethical. You are simply choosing a different way than intended to view open information. Kind of like reading the last chapter of a book first. Suppose that someone posted links containing the get statements to a web page and called it something along the lines of "Get your Harvard Info Here." This page could appear to be totally legit while totally screwing the people clicking the links. I think that this is a total over reaction on the part of Harvard.