QS - You shed an angle to this discussion I had not considered and I thank you for bringing it to the fore. "are men keeping two families who do not know about each other" hence giving ammunition to the scammers?
It would most definitely appear to be the case that this may be the root cause. Dishonesty from the offset.
Without making excuses for men who go on to father children outside of marriage - some of us ladies are not entirely blameless to what sometimes leads men to hide their 'falls from grace'! Gone are the days whereupon one was raised by more than one maternal mother in any given homestead...It's a case of "you dare stray out of this marital bed and I learn of it - you won't know what hit you" and you are damned if the evidence is there too! Getting half of the marital possesions will be the least of most men's worries! Back then, it was a case of how to protect your indiscretions from the wrath of your wife's/mistress' witchcraft towards the offspring - now it is the monetary assets no doubt...
So in comes the scammers who are very happy to settle the score on all fronts!
"Worrying is like a rocking chair: it gives you something to do, but it doesn't get you anywhere."