An employee of a public university was disciplined for engaging in "racial harassment" for reading a book called Notre Dame vs. the Klan: How the Fighting Irish Defeated the Ku Klux Klan. Apparently, the fact that the book had the phrase "Ku Klux Klan" in its title was enough to set the regulatory gears in motion. Paul Secunda has the details at Concurring Opinions.

While this book is actually a story of opposition to the Klan, I should note that in my view, even if the employee had reading a pro-Klan book it would be unconstitutional for him to face legal liability or punishment by the government merely because his choice of reading materials offended his coworkers.