New York governor Andrew Cuomo won't communicate with his staff by email — instead he uses a BlackBerry Messenger-specific feature to communicate via PIN, according to the New York Daily News. By sending messages directly to another BlackBerry's PIN (which is a unique device identifier), the message leaves no trace and is gone forever once deleted.

The problem with emails is they're awfully hard to eliminate with any certainty — email can propagate through several servers before reaching its destination, and even then an email can be recovered once deleted. Of course, no electronic messaging service is 100 percent secure — the Communications Security Establishment Canada says that PIN-to-PIN messaging should not be used to transmit sensitive data because a device can continue to receive PIN messages even after it's been lost or stolen. While Cuomo's actions may not be as transparent as his election campaign implied they might be, the former Attorney General can hardly be blamed for avoiding a digital trace. One needs only look to Anthony Weiner as an example of what can be... uncovered.