from this site:
http://www.templetons.com/brad/copymyths.html
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 important so that copyright law doesn't block your freedom to express your own works -- only the ability to express 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 usually a short excerpt and almost always attributed. (One should not use more of the work than is necessary 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.)
Note that most inclusion of text in Usenet followups is for commentary and reply, and it doesn't damage the commercial value of the original posting (if it has any) and as such it is fair use. Fair use isn't an exact doctrine, either. 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 words.
I'd like to know the answer to that too.
What's more, Google is a commercial website. They are paid for sidebar listing of websites and can even be paid for "top listing" of a site.
Google may have changed their dealings with the media though because they now also offer "Google News" to search just the wire services. Note too that "Democratic Underground" is considered a "news" source at Google News.