This discussion can be vast and extremely complex.
Not only music or videos, but any information as well can be "downloaded", too. And we won't even perceive it anymore. I'm not saying it is fair or not fair. But the reality is that the automation level of clicking here and there led most not to see much differences between what is free and what is not.
See the Service Manuals at HiFi Engine. They are free (PDF scans), but on eBay and other websites you pay for them (originals and scanned ones).
So, if something is free, would you pay for it somewhere else? The question may appear silly, but let's try to apply this to everything. This is just an example...<SNIP>...
Actually the service manuals brings up a topic that probably belongs in its own thread, the topic of orphan works. Sorry for the long winded post, but some context is required to understand the problem.
Not being a lawyer, here is my summary of the problem with orphan works. Service Manuals are a good example. To make a long story short, Service Manuals are copyrighted if published after March 1 1989 even without a copyright notice or if published prior that date with a copyright notice. (It is also possible that an item published between 1978 and 1989 is copyrighted if it was registered even though there was no copyright on the document. See
http://www.copyright.gov/circs/circ03.pdf ) So in many cases these are copyrighted works but the copyright holder has no interest in legally protecting their copyright or no copyright holder can be found. However unless the items have been officially released into the public domain by the copyright holder then under current law the distribution of these items is probably in violation of copyright law.
Since many of the Service Manuals were published by companies that are no longer in business or whose ownership rights have been confused via various mergers and acquisitions. Some of these works have become true orphans where it may be impossible to secure copyright release to distribute such works. However one could claim that it is in the public interest to allow such distribution. Copyright law, as far as I know, does not make any such exemption. Now distribution of limited sections of a manual could be claimed to be within the fair use doctrine, again another murky (and disputed) area of copyright law.
Many manuals are available for free or for download for a fee. Regarding downloads of true orphan works whether free or for a fee, neither are probably compliant for orphan works which are copyrighted. Those who are offering downloads for a fee are performing a service that allows the repair of equipment beyond the normal supported service life. Again I would argue that is in the public interest.
Taking the above into account, if the Service Manuals are available for a fee from someone who currently holds the rights to the Copyright then legally one should buy it from them rather than downloading for free. HOWEVER, if the item is not copyrighted then there is no reason not to use the free service. The legal morass, which is probably the most common case, is if neither distributor has the legal rights to the item in question and the item is not available from the copyright holder either because it is a true orphan work or the copyright holder has no interest in distributing the work. What do you do?
At this time, the only legal method would be to acquire an original hard copy of the manual, however, that may be impractical since these items were quite rare and have generally been destroyed by service centers when the items reached the "end of life."
Not trying to be political, but copyright law needs updating, but for some reason, every update seems to create more problems than are fixed.
It would be nice if copyright protection came with an obligation to make the information available to the public in a reasonable manner and that the copyright protection would lapse should the item no longer be available. Of course that probably won't fly since that is counter to several movie or show copyright holders who use the withholding of certain titles for a period of time to increase the demand for a re-release. To reiterate, every attempted fix has unintended consequences.
My layman's understanding is the Copyright landscape changed dramatically with changes in 1976 and 1978 since all items are generally considered to be copyrighted upon publication, even without a copyright notice.
One can spend tons of time with the reading material that can be found at
http://www.copyright.gov/circs