[justinhj]

There are ways to make sure that your GET requests are not cached. For example in the case we're talking about here the server sets that URI to have "Cache-Control: private; max-age=0". Now sure, a proxy could simply ignore HTTP protocol and cache it anyway, but that would break a lot of things and AFAIK is not seen often in the wild. Certainly in the case of the applications I worked on we did not have customers that reported connection difficulties over HTTP.