NEW YORK (AP) — Add hackers to the long list of things that give CEOs insomnia.

Target’s chief executive, Gregg Steinhafel, is the first boss of a major corporation to lose his job over a theft of customer data. His exit from the helm of the nation’s third-largest retailer on Monday shows that — in addition to guiding company strategy and keeping Wall Street happy with ever-growing profits— today’s chief executives are being held responsible for lapses in computer security.