This is an archived article that was published on sltrib.com in 2013, and information in the article may be outdated. It is provided only for personal research purposes and may not be reprinted.

Warning: Just because you buy and download a movie on iTunes or Amazon doesn't mean you actually own it.

That became painfully clear more than a week ago when Apple, Amazon and Disney decided to pull some of the studio's more popular movies from iTunes' and the Amazon digital store's catalogs. When they did, owners of these movies who bought and downloaded them before couldn't re-download or stream them again.

Initially, some thought it was a glitch. But when you try to download a copy of "The Lion King" or any of its straight-to-video sequels on Amazon's site, for example, you get a disclaimer that reads: "Due to our licensing agreements this video is currently not available for purchase or rental."

What that means is that Disney has to renegotiate with these digital distributors to put the movies back on the sites. In the meantime, if you bought them before, you're out of luck.

For consumers, especially parents who like to use Pixar movies as the go-to piece of entertainment for their fidgety children, it's a blow to what we know about consumerism — that is, if you bought something, you own it. Not so when it comes to digital movies and music. I think this is something customers ought to raise holy hell over.

You see, when you download a digital version of a movie or album, you don't own it outright in much the same way you do when you buy a Blu-ray disc or music CD. In those cases, you have a physical copy of the film or album and can do whatever you want with it as long as you don't violate copyright law such as make a copy of it to sell.

But the advantage with digital stores such as iTunes and Amazon is if you buy them, you should be able download them and re-download them whenever you want if you run out of hard-drive space. When you purchase something, Apple or Amazon keeps a record that you bought it. When you want to download or stream it again, you can without paying a second time because the service has a record that you bought it.

But Apple, for example, has had a history of inexplicably taking albums or movies off of iTunes so you can't download them again even if you bought them.

That's happened to me before. Several years ago, I purchased a Monty Python album and a video of "Saturday Night Live" skits. Some time later they were pulled from iTunes, and I couldn't re-download them anymore.

What most people probably don't know is that this practice is legal and mentioned in the "iTunes Store Terms and Conditions" statement that no one reads. It states:

"Some iTunes Eligible Content that you previously purchased may not be available for subsequent download at any given time, and Apple shall have no liability to you in such event."

This brings up a major flaw with the popularity of digital services and cloud storage. With everything from books, movies and music to documents and pictures turning digital, services that sell and store your digital content are expected to keep track of what you bought.

The problem is we can't really trust companies to keep our precious content for us. Disney's, Apple's and Amazon's decision to pull movies from their catalogs is an example of that. And what if a company that you bought a movie or song from loses the record of the transaction? That's happened to me once before when I purchased a game from Sony's PlayStation Network and they didn't correctly record the sale. We should scream at companies who pull these kinds of mistakes.

This kind of shoddy storage should encourage us to buy our entertainment on physical media like Blu-rays and make sure we back up all of our digital content on external hard drives (which defeats the convenience of having cloud storage in the first place).

Moves like this also encourage people to commit piracy or at least make digital copies of movies from Blu-rays (which actually is illegal). People will realize it's just easier to find a copy of a movie through file-trading methods such as bittorrent or illegal streaming services.

If we're all going to a digital world, we need to make sure it benefits us all, not just corporations.

If you have a tech question for Vince, email him at ohmytech@sltrib.com, and he'll try to answer it for his column in The Salt Lake Tribune or on its website. For an archive of past columns, go to http://www.sltrib.com/Topics/ohmytech.