Ideally we would like to see ISPs take a more active role in ensuring that their services are not being used to facilitate the exploitation of children. That doesn't mean they have to police the Internet; that's unreasonable. But certainly when they become aware of how their services are being used, they should be more proactive in cooperating with law enforcement.
Certainly at a minimum, when police come and ask for help, they have an obligation to assist. But if there are ways for them to be more proactive in trying to reduce the chances that their own services, what they're making money from, are being used to exploit children, that's an issue to be explored.