As a general rule, bloggers probably tend to obey "less rules" then news sites such as the A.P. and Reuters (although whose to say if AP writers don't occasionally news scrape from bloggers without giving credit, or ignoring salient points in their own report that a blogger has already discovered).
If the AP had it their way, everybody would pay for everything at all times, but this is not realistic. The AP, and Reuters, and so on, provide original content, then this content is purchased by regional newspapers all across the world.
However, if it were not for bloggers commenting on local and national news stories that they are interested in, The AP articles would have less impact. Bloggers actually provide a service called "Curation".
The problem of theft occurs when A, bloggers lift articles in their entirety, or even when over 20-25% of the article is lifted aka news scraping, and B. when no link back and credit is provided for either photo or articles that come from a news bureau or someone who has Paid for the right to publish the article.
If you blog, curate responsibly and give story and picture credit where it is due.