"If you buy a software CD box in a store, you OWN that software and can use it as long as you can find some hardware that will run it."
Not necessarily. If I go buy some boxed software, I automatically agree to the EULA. To install that software, I must explicitely agree to that EULA. That License Agreement could state something like "You may only use this software for 1 year." Come one year's time, the software manufacturer could demand that I either: 1. pay more money to renew the license, or 2. stop using the software. If I refuse, using the defense "Well, some guy on slashdot told me what's printed on the box or inside somewhere is totally irrelevant," I will probably get sued.