Don't think there is plagiarism because, in terms of copyright law, there is only protection of expression rather than ideas. The reason why the publishers of the book 'Da Vinci Code' were unsucessfully sued was because Dan Brown copied ideas of other people for his story rather than expression - in other words the stuff about bloodline and the Knight Templars was such a broad and abstract idea that it didn't constitute copying the previous authors' 'expression' but was just a copy of their general and abstract 'ideas'. Thus, when it comes to case summaries, I'm pretty sure that they would only constitute 'ideas' rather than a unique 'expression', thus there's no copyright infringement.