Vacation as Fraud Detection

The coverage of Jerome Kerviel has revealed a number of low tech precautions which financial institutions employ, most of the time with success, but none so novel as the "forced vacation."

Via WSJ:
Many big Western banks have a rule of thumb that traders be required to take holidays for at least five workdays in a row, and often 10. This isn't an effort to undercut the work ethic. It is just hard to keep a fraud going when the day-to-day management of an order book is being handled by someone else.