[PinkiesBrain]

There should be internet 2.

Kick off all ISPs which refuse to do good ingress/egress filtering. Kick off all customers which absolutely positively need to be completely exempt from the filtering because of their ultra special snowflake networks, when creating source spoofed abuse a couple times. So now you have an internet with reliable source IPs. Allow ISPs for their customers to push firewall rules blocking abusive traffic to the originating ISP, subject to some fair use rules. If an ISP's firewall slows down because they are overloaded with rules for obvious abuse from their customers ... well that's working as intended then.