They could probably be quickly found if someone is looking for them, but carriers don't necessarily care that much about these. Add a couple layers of indirecti

They could probably be quickly found if someone is looking for them, but carriers don't necessarily care that much about these. Add a couple layers of indirection with MVNOs and there's a lot of meh to spread around. If the reporting around this is accurate, sounds like someone(s) was swatting through these, which brought the attention needed to find this group.