Law enforcement in various jurisdictions are catching up with these types of emails. I know some that encourage people to report these types of emails. They are straight-up blackmail and that often falls under different laws than phishing. Please check what your local law enforcement has in place in your area.
Secondly, because this is new, people are not equipped to know how to respond to this, so reporting to your local IT department can be important so they can block them and chase up with other employees who may have received the same email in your company.
I got a panicked email from a security admin a few months ago with the same type of email, and he was asking the same question you did. While I worked with the local LE, I also asked the security admin if there were copies of the email in other people's inboxes. It turned out that 15 people received the email, only one reported it, and they were all freaking out. Some were trying to figure out how to pay the blackmailer (the amount, in this case, was much lower).
So, check with your local LE, and do make sure your IT department knows about it so they can help the poor souls who are freaking out.
Once this becomes more mainstream, our responses can become more standard.