Faster to just scan the zonefiles. You run into a black swan problem with this technique. However, that said, all of them WERE registered, TWICE throughout hi

Faster to just scan the zonefiles. You run into a black swan problem with this technique. However, that said, all of them WERE registered, TWICE throughout history. Once way back and again more recently (someone wrote 2007, sounds about right). People have realized the cost of holding them is higher than the potential sales in many cases, especially at the bottom of the quality barrel. They weren't kept because they sucked but domain investors like all people like patterns and herding and get sucked into poor investments.