SMURF amplifier block list - READ THIS

Karl Denninger said once upon a time:

We already do this - its not a perfect filter, but it will only let you
transmit packets with sources that COULD possibly come from us.

The puzzling thing is why anyone would want to transmit packets over their
for-cost links with an address that wasn't from their network. Proper
filters have other benefits aside from the obvious attack issues.

To create havoc on other people's networks?