Premise: Some of the emails had the subject line, "Think Twice." They were sent from a spoofed email address. The sender claimed to have had an associate plant a small bomb in the recipient's building and said the only way to stop him from setting it off was by making an online payment of $20,000 in bitcoin.
Hypothesis: Authorities would go on to undo the email's spoofing, and uncover the person that sent the emails.