[oger]

Great writeup. Simple heuristics very often work wonders. The fraudsters are out there and try to pinch holes in your shield. Some time ago we were running a mobile service provider and had some issues with fraudulent postpaid subscribers - however the cost of using background checking services was substantial. We solved it quite effectively by turning the background checks on when the level of fraud went over a certain threshold which made them go away for some weeks. We kept this on and off pattern for a very long time with great success as it lowered the friction to sign up significantly when turned off…