There are some publishers that do go after sites for publishing their stuff. I've seen the Gateway Pundit go after people before who consistently repost their articles. You can do it under fair use by not posting the entire article, just exerts instead, plus full credit to the publisher. I've been blogging long enough to know most don't care, if you post up articles on sites some allow the full display of the article while others require you to keep it to a few lines or paragraphs. I am assuming music artist and book publishers would be totally different at times.