Besides making pictures telling John Grisham to fuck off (as satisfying as that is).
For everyone who is struggling with the fact that they put money in John Grisham's pocket - a donation to The National Center for Missing and Exploited Children (fondly known as NecMec by those of us in the business) of the amount that you would have spent on his new book might make you feel better.
The book is on sale for 17.37.
Link here: https://secure.missingkids.com/Home
Or, in the alternative, pick your favorite child protection charity and send them a donation.