Sophisticated cyber-attacks on company systems may get all the attention, but the most common cause of data breaches isn’t hackers; it’s usually little more than simple human error.

According to a recent study by the Society of Corporate Compliance and Ethics and the Health Care Compliance Association, data breaches most commonly stem from negligence by rank-and-file employees: laptops left in taxis, smartphones forgotten on a restaurant table, or misplaced thumb drives. In fact, the most common cause of data breaches—lost paper files—is decidedly low tech, the survey finds.

Jaclyn Jaeger is a freelance contributor to Compliance Week after working for the company for 15 years. She writes on a wide variety of topics, including ethics and compliance, risk management, legal,...