Many of us on the internet quote from other sources, giving the attribution of the source and often linking to the original article. But in the future we can be running afoul of the copyright law if we quote too much.
Unfortunately, what constitutes too much under the "fair use" statute of copyright law doesn't include a legal word limit. Bloggers and website content people are left to their own discretion.
To learn more about this subject, read Brian Stelter's March 2nd New York Times article "Copyright Challenge for Sites That Excerpt." (I'm not going to quote any of the article here -- I don't want to risk being in violation of the "fair use" statute when it comes to The New York Times.)
Phyllis Zimbler Miller is the author of MRS. LIEUTENANT: A SHARON GOLD NOVEL and the co-author of the Jewish holiday book SEASONS FOR CELEBRATION. She also blogs at Mrs. Lieutenant and Operation Support Jews in the Military, and she is the co-host of the BlogTalkRadio show Your Military Life. Her company Miller Mosaic LLC builds call-to-action websites for book authors and small businesses.