IT is, as this article by Jos Creese puts it, the scapegoat of a company when it comes to any IT-enabled change. Truth is, IT has to learn that being blamed just comes with the job, and becoming defensive or aggressive will only lead to more headaches down the line. Creese gives a few tips on reducing this pain: admit when IT doesn't perform well, address problems quickly, and think laterally. Another key point is to think less like a IT organization and more like a retailer:
Learn from the retail sector. Experience there shows that responding well to a complaint raises the customer's satisfaction above its level before the incident that caused the complaint. Always be sympathetic to the impact of any loss of IT service on frontline staff and be seen to empathise – or preferably visit them.
In the end, a CIO would do well to understand that they can't personally look after every help desk ticket or explain why every request isn't possible, but trying to respond to complaints (and keeping a firmly positive attitude) without taking it personally goes a long way to reducing stress.