The cheaters deserve to be outed. Fuck 'em, let the world know their word is worthless. And as to the question as to whether they're actually cheating or not, let's be honest here - precisely nobody signed up for a site who's advertising and stated reason for existing is explicitly about sneaking around behind your spouse's back, without the intent to be sneaking around behind your spouse's back.
And comparing outing cheaters to terrorists, seriously?
That said, it doesn't mean that they deserve to have their identities stolen. More acceptable would have been names and emails without all the credit card and other personally identifying info.
It's just a toxic, evil, repulsive scene.
You know what's toxic, evil, and repulsive? Entering into a committed relationship with one person, and rather than being an adult and breaking it off if it's not working, sneaking around behind their backs while leading them around as if you're remaining faithful. As far as I'm concerned, cheating is near the top of the list of horrible things you can do to another human being.
I fully expect this sentiment to be a barely-visible shade of "disagreed with the rest of the site light grey" by the end of the day.