A husband suspects an online affair (Sample Scenario from the CSTB)

John and Sally "meet" on a bulletin board provided by a commercial network operator and then begin corresponding through e-mail. The operator has a "standard' set of acceptable use policies that prohibit sending (through e-mail) or posting (on either type of bulletin board) any 'defamatory, obscene, threatening, sexually explicit, ethnically offensive, or illegal material." John receives a private e-mail note from Sally's husband saying: "I know what's going on between you two, and I'm not putting up with it. It's too late to save her. She's a gonner." John notifies the operator and forwards a copy of this note, requesting that the operator notify the local police in Sally's home town (since John has no way of knowing where Sally lives).

Questions

1. Does the operator have any legal responsibility to notify the police? If John had not contacted the operator, would it have any liability or responsibility?
2. Should the operator provide John with Sally's address so he can notify the police if he wishes?
3. If the operator decides to notify the police and they arrest the husband, only to find out that a prank was played by Sally, does the husband have any claim against the operator?
4. If the operator decides not to notify, the police and it turns out that Sally was killed by her husband a day after John notified the operator, does the operator have any liability to Sally's heirs? How do "Good Samaritan" laws apply in this case?