General Discussion
In reply to the discussion: Not everything you buy is actually yours to keep.-Amazon blocks videos already bought by customers. [View all]sharp_stick
(14,400 posts)Of course nothing stops Amazon, or Vudu, or any other streaming service from changing the rules as this from Amazon Instant Video Terms of Service.
"Availability of Purchased Digital Content. Purchased Digital Content will generally continue to be available to you for download or streaming from the Service, as applicable, but may become unavailable due to potential content provider licensing restrictions and for other reasons, and Amazon will not be liable to you if Purchased Digital Content becomes unavailable for further download or streaming. You may download and store your own copy of Purchased Digital Content on a Compatible Device authorized for such download so that you can view that Purchased Digital Content if it becomes unavailable for further download or streaming from the Service."
http://www.amazon.com/gp/help/customer/display.html?nodeId=200026970
It looks like your only recourse is to actually download it if you really want to keep it.