Depends on whether or not the Registry wants their TLD to be associated with spam/malware distribution/botnet C&C/phishing/pharming and be removed at resolvers via RPZ or similar. Ultimately, the Registries are responsible for the pool the Registrars are peeing in -- it's the Registry's namespace, is it not? it's not clear, to me, that any of those hammers have real effect.
Not sure the RPZ hammer has been brought out in force yet. I've seen a few recommendations on various mailing lists, but no concerted effort. Unfortunately, there is no easy/scalable way to determine who a registrar for a given name is, so the hammer has to be applied to the TLD as a whole, which has unfortunate side effects...
I love how people love to blame ICANN.
but, they are the names and numbers authority, no? it says so in their name.
"Internet Corporation for Assigned Names and Numbers" -- Don't see "authority" in that name. :) Regards, -drc (speaking only for myself)