Re: 'They've already been copied a dozen times for further use.'
AC: You don't know. Shadow Brokers could have had plenty of buyers, not via the auction route. The auction was plausibly a publicity stunt. Of course, "Corporation X", for any X, would get more value from buying exploit Y if World Z does not know about it. Having sold all they were going to sell (which is also how the original story goes), Shadow Brokers had no incentive to keep hiding the goodies, and credibility to gain by releasing.
Biting the hand that feeds IT
