My sister got one of these. She ignored it. Nobody’s spammed her Facebook so far.
It’s a brilliant scam, really. Your hit rate has to be maybe 1 in 10,000 and you’re rich. Hell, it doesn’t even matter if you got the email address from the leak. Maybe the address wasn’t even in the leak. Some people are suckers.
That’s pretty much how it is with any spam. Until there’s some cost structure that makes ultra-high-volume-e-mails unfeasible unless a real profit will result, that fact will remain true.
WOW–Thank you for posting this! I learned a lot!
You see, folks…you’re all missing the point. This isn’t a blackmail attempt.
It’s an educational* email, explaining how to buy a bitcoin.
So----Ignorance Fought, in the best spirit of the Dope. !
And I sugggest that, as a reward, we offer the spammers a really valuable prize: a special deal— A reduced price for membership here at the Dope.
The regular fee is a thousand dollars, right? But we’ll give it to them, if they respond within 48 hours—for only $500.
They can pay in bitcoins, of course. 
*Seriously! I’ve heard of bitcoin; but till I read this, I had no idea how to actually buy one. But now I know.
You are assuming, of course, the the blackmailer is instructing you to send a Moneygram (which may be picked up by anyone in the world who knows the serial number) to a reputable purveyor of bitcoins.
(I have no idea if they are.)
It looks like AM has given up pretending that there are a lot of women on the site:
Warning: NSFW
I wonder how many bitcoins they got Josh Duggar for?
Ick! Don’t they know that sucking off a dude who smokes a cigar is like sucking off an ash tray?
Note that more evidence emerged that there were in fact a significant number of women on AM. It was a popular and successful dating site for gay women.
They didn’t show up in the initial count, because they weren’t getting spammed by fake women, which (it turns out) was what the original count was counting.
You can generate as many Bitcoin addresses as you want. So, presumably, the scammer is putting a unique address in every email, and they’ll know who paid if any of those addresses gets money.
I think that you should tell them in just those words… and then tell us what they say.