Spouse pulling a credit report on partner Other Debt

How difficult is it to find out who ran your credit report if it wasn't a corporation? My friend recently obtained her husbands credit report without his permission being she suspected he wasn't being honest. He claims he'll press charges if he finds out she did this. No harm has been done to his credit, but this does violate his privacy rights. What would the penalties be and is this something that you can be arrested for?