According to a recently released Proofpoint survey (free copy available), 41 percent of large U.S. corporations employ staff to read employee e-mail, and 26 percent have terminated employees for e-mail policy violations in the past year. Proofpoint, a computer security firm, conducts an annual survey of outbound e-mail and data loss prevention issues in large companies.

The survey also found that 44 percent of the surveyed companies investigated an e-mail leak of confidential information in the past 12 months; 23 percent said their business was impacted by the exposure of sensitive or embarrassing information; and 34 percent of the largest companies (20,000 or more employees) reported that employee e-mail was subpoenaed in the last 12 months.