The copyright trolls like Righthaven are also going after excerpts AND images. This isn't about protecting the rights of authors and publishers, but rather is akin to ambulance-chasing. Righthaven buys up rights to content for the specific purpose of filing suit against unauthorized users. They target smaller venues and users who are more likely to settle for a few thousand dollars
than fight in court.
Google 'righthaven copyright lawsuit'
Here's a post that gives some defensive strategies:
http://www.godlikeproductions.com/forum1/message1146844/pg1

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