Now it's AshleyMadison wives who are receiving blackmail letters.

"The continuing story of the Ashley Madison hack, and its repercussions, has taken another ugly twist.
As before, I would recommend that anyone who receives a blackmail threat through the US Postal Service contact the US Postal Inspectors Service and FBI so that they can investigate. I haven't seen any reports of Ashley Madison blackmails being sent by post outside the United States."
https://www.grahamcluley.com/2016/03/ashley-madison-wives-receiving-blackmail-letters/

Fake profiles are wooing lonely hearts on sites far beyond AshleyMadison
http://onlinedatingsoundbarrier.blogspot.com.ar/2016/02/fake-profiles-are-wooing-lonely-hearts.html