No matter who hacked the site, if any info is sold to predators who find victims online, it could be far more serious than just exposing a bunch of people’s sex lives to public ridicule-extortion is the least thing that could happen-remember the Craig’s List killer and the Long Island serial killer?
Adulterers hurt other people. Betrayed partners (and those who were hurt in other ways) expose the betrayal. My sympathy here is pretty thin.
Not only were they cooling around, they were so stupid they left a trail in a venue where what has happened was likely to happen essentially. Libidos aren't very smart. Don't let them be in charge of your actions.