Fair use has become an essential concept to many bloggers, who often quote portions of articles before discussing them. The A.P., a cooperative owned by 1,500 daily newspapers, including The New York Times, provides written articles and broadcast material to thousands of news organizations and Web sites that pay to use them.

Last week, The A.P. took an unusually strict position against quotation of its work, sending a letter to the Drudge Retort asking it to remove seven items that contained quotations from A.P. articles ranging from 39 to 79 words.