Due to it being out of our control as to what happens in the cloud, well let's ask Steve Wozniak about the cloud. OK?
http://www.cnet.com/news/woz-the-cloud-is-a-nightmare/
http://www.cnet.com/news/wozniak-criticizes-cloud-dependence-in-light-of-nsa/
If you own content, keep it local and on backups to be safe. As to the iTunes purchase it's a deep problem of what you actually purchased. That is, the original "content provider" can bail out of iTunes and demand their content be removed. Now it's a legal reading of what's in those contracts to see if you have any recourse but we all know that until you get a copy unbound from their cloud and DRM it's not yours to keep.
Screaming yet?
A purchased movie from iTunes is no longer "purchased" by my account. So I wrote in and asked for access to my purchase and they said:
Thanks for choosing Apple.
Hi ***
Thank you for writing back to us. It’s Arie once more, your iTunes Store Advisor.
***, after some investigation, I can see they may have been removed or modified and are no longer available.
Below are some options if you’re not able to re-download any of your past purchases:
• Check your hard disk for unavailable items. This article explains how:
If your music is missing from iTunes
https://support.apple.com/HT203167
• If you have any of the items on an iPhone, iPad, or iPod touch, you can use iTunes to transfer them to your computer. For more information, see this article:
https://support.apple.com/HT201267
I hope you understand that iTunes Store is only a store front that gives content provider a place to sell their content. The content provider is the one who is in charge of pricing, posting updates and also has control of removing their content. If they have chosen to change something, the iTunes Store must abide with this decision.
Your patience in this matter is greatly appreciated.
Sincerely,
Arie
iTunes Store/Mac App Store Customer Support
http://www.apple.com/support/itunes/ww
The movie is still there but I have to purchase it again if I want to watch it. So theoretically, they can modify or change all the movies and songs and it would not be able to be transferred along with your account? Are they not boosting that with Apple TV and such that you have access to your purchases where ever you use your account? Should I store my stuff on iCloud to protect my purchases then?
They make it a bit difficult to transfer purchased item to other computers that do not have the same iTunes account in the name of protecting the copy right and discourage use of the material outside of iTunes and yet when this happens, it was an "outright" purchase.

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