It's taken me upwards of 6-9 months to terminate employees for performance issues. Federal laws make it very hard to terminate without clear and distinct cause, which can be anything from performance to lying/stealing/breaking the law to insubordination to downsizing and so on. But no, I really don't think I could just terminate someone for publishing a book I find offensive and for giving it to his co workers. Technically the book is the employees' property and is not an illegal substance or other item that isn't allowed to be distributed.
But I've never had to confront it so I have no idea. I'm just saying IMO it isn't as cut and dry as I think some people assume it is.
Horse sense is the thing a horse has which keeps it from betting on people. ~W.C. Fields