Hackers are sending emails to forum members threatening to expose their porn viewing habits and hold their systems hostage. They try to make it appear that the email came from your own email account. They tell you the password they hacked form the forum as proof they hacked your system—trying to snare those that use the same password on email and on forums.
Then they demand that you send bitcoin to them.
You should either ignore these or file a complaint with the FBI.
You should make sure that your email and system passwords are different from what you use on forums.
Do not click on any links in such emails.