What are some of the ethical implications of what occurred at WorldCom?

https://www.sec.gov/Archives/edgar/data/723527/000093176303001862/dex991.htm#ex991902_1

List the key issues involved in this case.
What are some of the legal implications of what occurred at WorldCom?
What are some of the ethical implications of what occurred at WorldCom?
Do you think that this scandal could have been prevented or detected? How?