Conversation so far:
Did Brown commit copyright infringement?
In August 2005 author Lewis Perdue unsuccessfully sued Dan Brown for plagiarism.
Did Dan Brown write novels?
In 1996 Dan Brown quit teaching to become a full-time writer. Digital Fortress was published in 1998.
What other novels did Dan Brown write besides Digital Fortress?
Dan Brown also co-wrote a humor book with his wife, 187 Men to Avoid: A Survival Guide for the Romantically Frustrated Woman.

Question: Were there other copyright cases?
Self-contained rewrite: Were there other copyright cases besides Lewis Purdue suing Dan Brown?