Newsvine is a news aggregator, a source of original news commentary and reporting, and a social network for discussion of the news. When you seed an article you typically quote a small portion of it and provide a mini-review of the content, so that someone reading the seed can decide whether they want to follow the link and read the actual source. When writing an article it's common to make use of other people's ideas and information. Links and quotations clarify and document the sources of these ideas and provide evidence to support assertions you make. The same thing happens in discussion threads - it's far more effective to provide a link or a quotation when making a point, readers appreciate the chance to see why you have said what you have and they may enjoy the opportunity to read further into the material you have referenced.
Doing this properly isn't difficult, and it's important so as to avoid the Scylla and Charybdis of copyright and plagiarism.
Copyright is the legal concept. It's about having the legal right to reproduce someone else's work. Plagiarism is the moral concept. That's about making it clear which material is written by you and which is a copy of something written by someone else. Newsvine adds a third restriction: you may not seed your own website, although you may reproduce an article from your own site in your column on Newsvine.
I'll start with this since it's easier. If you quote material that you didn't write yourself you must attribute it to the author. That means you need to mark it up as a quote (preferably with <blockquote> or <q> tags) and say who it was who said it first. At the very least say something like I saw someone write in the NYT that... Best of all say something like
To add a link you use the
<a>tag, like this:
The <a href="http://help.newsvine.com">help group</a> homepage.
Ok but what if you paraphrase rather than quote verbatim? The general rule is that if you've borrowed an original idea and it's of any importance in your argument then you should attribute it as a matter of courtesy. You don't need the <blockquote> but you can either introduce the idea: As Steinmetz says, if you keep still, you are meditating. or you can provide a reference after you explain the idea. Leaving out expectation is the trick. Don't "make" anything, just sit there. [Steinmetz] If you can't link for any reason, then say where you got it from, at least in general terms. Was it a book, a radio show, or even a private conversation? Say so.
It's simple really - let people know what is yours and what you borrowed.
If this is more difficult it's only because lawyers have gotten involved. The author of any work printed or broadcast or recorded - including artwork, software code, choreography, designs, the lot - owns that creative expression. They don't own the ideas on which that expression was based, or the facts (scientific, historical, or biographical) embodied in the expression, but you may not reproduce the words or sounds or brushstrokes or whatever without the author's permission. By the way all works published before 1923 in the United States are in the public domain but pretty much everything since then remains under copyright, even though it will lapse eventually.
So that would be that - no copying - but for the exemption called fair use.
The courts base decisions about fair use on the following:
a) Is it a competitive use? (In other words, if the use potentially affects the sales of the copied material, it's usually not fair.)
b) How much material was taken compared to the entire work of which the material was a part? (The more someone takes, the less likely it is that the use is fair.)
c) How was the material used? Is it a transformative use? (If the material was used to help create something new it is more likely to be considered a fair use that if it is merely copied verbatim into another work. Criticism, comment, news reporting, research, scholarship and non-profit educational uses are most likely to be judged fair uses. Uses motivated primarily by a desire for a commercial gain are less likely to be fair use).
Mostly this isn't hard to decide on Newsvine. If you're quoting a piece of something in an article or a comment thread, to back up a point that you're making, then it's almost certainly fair use unless you took far too much of it. But seeding is more problematic, because you're often quoting from something which is short and it can be hard to get enough of it to get the idea across without having taken half the article. I'm guilty of this myself, and the answer is not to be lazy: paraphrase the idea contained in the article, or else write a teaser which introduces the idea without trying to explain it all in detail.
Stanford publishes a helpful guide to fair use here. Go read it if you're not sure, they say it better than I could. One thing to notice, though, is that it's very difficult to make fair use of any portion of an artwork, video, song, or map. But Flickr publishes a lot of material which is usable under creative commons attribution, and a lot of US Government material including photography is public domain by law.
So look at it this way: our work here on Newsvine is a sort of collaboration. We comment on one another's ideas, we bring in references and ideas from outside. The concepts of copyright and plagiarism are how we play nice. Give attribution to the writing and ideas you borrow. Make fair use of other people's original material.