I questions have about Amazon CloudFront. I see the CloudFront Private Content info states "When you create signed URLs for your objects, you can specify specify an ending date and time, after which the URL is no longer valid". So, this means you can specify when the url will expire and when it expires, the url is gone and cannot be accessed, correct? Example: A user purchases a video from my website. The user is given a url to view it or download it. You specify the url to last 1 hour. The user has 1 hour before the url disappears. It then cannot be accessed anymore? Does a viewed video from a website typically get cached by the viewer? If so, after an hour can it still be viewed from the viewers' cache? And if the video URL is copied it won't be able to be replayed by some thief after 1 hour? Any insight you can share will be greatly appreciated.