I am certain that you understand that the concepts associated with the words in the title are clearly different. It seems to me that your definition of plagiarism is more related to copyright infringement than to plagiarism. You write, <i>For journalists -- since we're talking about journalism -- plagiarism consists of using, as your own, words you don't own. And regardless of whether you approve, we do not always own the words that we write.</I>
A definition of plagiarism from journalism.about.com is, <i>plagiarism means claiming someone else's work is your own by putting it in your story without attribution or credit.</i> This is how I have used the word all along, and it is different than the definition you gave.
Let's try an example. I copy an article form the New York Times and publish it in the Bixography website without explicit permission from the New York Times. I can envision two situations.
- I give the exact reference. That is a copyright violation.
- I do not give the source and pass the work as my own. That is plagiarism.
As to ownership, let me cite the definition of authorship from copyright.gov
<i>Under the copyright law, the creator of the original expression in a work is its author. <b>The author is also the owner of copyright </B>unless there is a written agreement by which the author assigns the copyright to another person or entity, such as a publisher.</i>
This is how I have viewed all along ownership of text. If I write an article, I am the author and owner. Granted that most, if not all, reporters assign copyright to the journal, newspaper, or magazine that publishes the article. I have written over 100 articles in scientific journals and chapters in books, mostly in the US, but also abroad. Reluctantly, I assigned copyright to the medium that published my article. But I am still the author and, strictly in an moral rather than a legalistic view, I consider myself the owner. The only reason I assigned the copyright to the publishers of my articles and chapters is because they have me over a barrel: they would not publish my work unless I assigned the copyright to them.
Copyright infringement is a violation of the law. Plagiarism is an ethical and moral disgrace.
Copyright infringement can also be an ethical violation. If I make 100 copies of a CD without permission of the owner, and sell them, I am also commiting an ethical violation.