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.
No one that was emailed fell for the demand. 
( z1 fall :ARG1 ( z2 no-one :ARG1-of ( z3 email ) ) :ARG2 ( z4 demand ) )