You hire John Smith to sell your product. You expect him to develop a broad customer base through referrals and direct sales. As part of this venture, John studiously builds contact lists on social networking sites such as Facebook and LinkedIn. Like most people, John mixes business with pleasure — resulting in a substantial list of online contacts that includes relatives and friends as well as business contacts.

After several years, John announces that he is leaving your company to work for a competitor. He promotes his new position on his Facebook page and updates his LinkedIn profile. In the wake of John’s departure, are there any steps you can take to prevent John from using these contact lists to solicit your clients for his new business?