Re: why, why, why... what is the point?
Have you ever used an open WiFi access point? On an insecure, shared, WiFi network, it is trivial to modify plain HTTP traffic to serve up porn, ads, or exploits which install malware on computers.
Do you absolutely trust your ISP? Do you absolutely trust every employee at your ISP? Your ISP can see *everything* you do in plain HTTP. And, like the above WiFi situation, your ISP (and any technical employee thereof) is in the perfect man-in-the-middle position to modify all of your insecure traffic - with or without official blessing of the company.
So then tell me: Why should we *not* secure websites?