I was working at a company (no, really) where the CIO got ticked off about receiving a chain letter via company e-mail. She sent out a very harshly worded e-mail forbidding chain letter forwarding, and threatening to terminate anyone who violated the policy.
The next day, I received an e-mail from a clever young lad, Marcus Everidge, whom I was managing. It said, in so many words, "Attached is a very important message from the CIO. Please forward it to at least five people within the hour, or you will have very bad luck."