mrtoken: there is a couple of problems.
Notice this in the story
A lawsuit "See Ashley Madison fake profile lawsuit; 90-95 per cent of actual users are male."
Sounds like there are a lot of fake woman profiles made by the owners of the site.
And
But as Wired notes, Ashley Madison's sign-up process does not require verification of an email address to set up an account.
So anyone could put in Johns email address without john knowing
There are so many that there is a lawsuit from a woman who claims that she developed RSI from creating fake profiles. In their court filings A-M did not deny that the woman was employed to create fake profiles.