I believe the auctions aren't just children, different tastes spawn different markets. The whole point is that this is simply slavery. Some are for sex, some are for torture and murder, some are for black market organ harvesting. As far as organic terrorist activities vs coordinated ones, I think most organic ones are easily disrupted, because of all the surveillance, however if one serves the interests of the government, not only will it be "overlooked", they can be supported and enabled with materiel and expert guidance.