The actual solutions are: 1) Egress filtering by the ISPs 2) Better malware resistance and vulnerability mitigation on easily-compromised appliance and IoT de

The actual solutions are: 1) Egress filtering by the ISPs 2) Better malware resistance and vulnerability mitigation on easily-compromised appliance and IoT devices But neither is going to happen. 1 is a coordination problem. It has to be all or nothing, which can only be compelled by law, and we have no global laws and no global law enforcement mechanism. Some countries inevitably don't care and the rest won't partition the entire Internet by permanently cutting them off. 2 would probably make the entire Internet of Things and a whole lot of home computing just not happen because it isn't economically feasible. Poor security effectively acts as a tacit tax. We all pay a little bit each, but the tax is collected by criminals instead of governments. Note that even your proposed solution here only works if 1 happened. Otherwise, source IP spoofing easily defeats a blocklist.