You have requested data that the server has decided not to provide to you. Your request was understood and denied.
Well screw you, server! How mean is that? "Um, yeah, we got that turkey you were looking for, and, well, we've decided not to give it to you. Not that we can't, we just won't. Yeah, we understand what you mean by 'turkey,' but we're going to go ahead and deny that request."
Has anyone seen my stapler?