The result? The hacker now has all of the e-mail addresses that you forwarded the email to, along with those of the next person and so on. Notices about grave consequences are normally send by authorities on the subject matter... For example, Symantec or McAfee (computer security companies) would send out notices about computer threats, viruses, trojans, etc.
Passing on the emails to your address list is doing exactly what the hacker wants you to do! Remember, be judicious in forwarding emails, including jokes, to the members of your address list. Following this advice will help reduce spam, identity theft, and other malicious threats to your confidentiality.