The receptionist

His trick

Our happy receptionist takes the open-door policy a bit too far. He leaves the visitor log unattended for hours at a time, and dutifully signs people out at the end of the day. Even worse, the corporate ID badge-making machine is located on his desk in a public area. Every morning he logs in as "Administrator," then leaves for the first of the day's half-dozen coffee breaks.

Your treat

Duplicate his badge with the photo of Adam Yahiye Gadahn (California's own contribution to al-Qaeda), and use it for door access to sensitive areas for a week. Send it back anonymously through interoffice mail. Wait a few days, then ask to review the logs because of an apparent anomaly. Suggest that a supernatural event might have occurred when you recall a visitor having a heart attack and near-death experience on premises, yet "5pm" appears in the OUT column on the visitor log.