Copyright and interpretation

Copyright and understanding of it   This is snipped from http://www.templetons.com/brad/copymyths.html (go there for the full article) , for discussion:

4) "My posting was just fair use!"

See

EFF notes on fair use and links from it for a detailed answer, but bear the following in mind:
The "fair use" exemption to (U.S.) copyright law was created to allow things such as commentary, parody, news reporting, research and education about copyrighted works without the permission of the author. That's vital so that copyright law doesn't block your freedom to express your own works -- only the ability to appropriate other people's. Intent, and damage to the commercial value of the work are important considerations. Are you reproducing an article from the New York Times because you needed to in order to criticise the quality of the New York Times, or because you couldn't find time to write your own story, or didn't want your readers to have to register at the New York Times web site? The first is probably fair use, the others probably aren't.
Fair use is generally a short excerpt and almost always attributed. (One should not use much more of the work than is needed to make the commentary.) It should not harm the commercial value of the work -- in the sense of people no longer needing to buy it (which is another reason why reproduction of the entire work is a problem.) Famously, copying just 300 words from Gerald Ford's 200,000 word memoir for a magazine article was ruled as not fair use, in spite of it being very newsworthy, because it was the most important 300 words -- why he pardoned Nixon.
Note that most inclusion of text in followups and replies is for commentary, and it doesn't damage the commercial value of the original posting (if it has any) and as such it is almost surely fair use. Fair use isn't an exact doctrine, though. The court decides if the right to comment overrides the copyright on an individual basis in each case. There have been cases that go beyond the bounds of what I say above, but in general they don't apply to the typical net misclaim of fair use.
The "fair use" concept varies from country to country, and has different names (such as "fair dealing" in Canada) and other limitations outside the USA.
Facts and ideas can't be copyrighted, but their expression and structure can. You can always write the facts in your own wordsthough
See the DMCA alert for recent changes in the law.

5) "If you don't defend your copyright you lose it." -- "Somebody has that name copyrighted!"

False. Copyright is effectively never lost these days, unless explicitly given away. You also can't "copyright a name" or anything short like that, such as almost all titles. You may be thinking of

trade marks, which apply to names, and can be weakened or lost if not defended.
You generally trademark terms by using them to refer to your brand of a generic type of product or service. Like a "Delta" airline. Delta Airlines "owns" that word applied to air travel, even though it is also an ordinary word. Delta Hotels owns it when applied to hotels. (This case is fairly unusual as both are travel companies. Usually the industries are more distinct.) Neither owns the word on its own, only in context, and owning a mark doesn't mean complete control -- see a more detailed treatise on this law for details.
You can't use somebody else's trademark in a way that would steal the value of the mark, or in a way that might make people confuse you with the real owner of the mark, or which might allow you to profit from the mark's good name. For example, if I were giving advice on music videos, I would be very wary of trying to label my works with a name like "mtv." :-) You can use marks to critcise or parody the holder, as long as it's clear you aren't the holder.

6) "If I make up my own stories, but base them on another work, my new work belongs to me."

False. U.S. Copyright law is quite explicit that the making of what are called "derivative works" -- works based or derived from another copyrighted work -- is the exclusive province of the owner of the original work. This is true even though the making of these new works is a highly creative process. If you write a story using settings or characters from somebody else's work, you need that author's permission. Yes, that means almost all "fan fiction" is arguably a copyright violation. If you want to publish a story about Jim Kirk and Mr. Spock, you need Paramount's permission, plain and simple. Now, as it turns out, many, but not all holders of popular copyrights turn a blind eye to "fan fiction" or even subtly encourage it because it helps them. Make no mistake, however, that it is entirely up to them whether to do that.
There is a major exception -- criticism and

parody. The fair use provision says that if you want to make fun of something like Star Trek, you don't need their permission to include Mr. Spock. This is not a loophole; you can't just take a non-parody and claim it is one on a technicality. The way "fair use" works is you get sued for copyright infringement, and you admit you did copy, but that your copying was a fair use. A subjective judgment on, among other things, your goals, is then made.
However, it's also worth noting that a court has never ruled on this issue, because fan fiction cases always get settled quickly when the defendant is a fan of limited means sued by a powerful publishing company. Some argue that completely non-commercial fan fiction might be declared a fair use if courts get to decide. You can read more

7) "They can't get me, defendants in court have powerful rights!"

Copyright law is mostly civil law. If you violate copyright you would usually get sued, not be charged with a crime. "Innocent until proven guilty" is a principle of criminal law, as is "proof beyond a reasonable doubt." Sorry, but in copyright suits, these don't apply the same way or at all. It's mostly which side and set of evidence the judge or jury accepts or believes more, though the rules vary based on the type of infringement. In civil cases you can even be made to testify against your own interests.