It should be pointed put that the ISPs have their share of blame for the
quick-spreading worms, beause they neglected very simple precautions --
such as giving cutomers pre-configured routers or DSL/cable modems with
firewalls disabled by default (instead of the standard "end-user, let only
outgoing connections thru" configuration), and providing insufficient
information to end-users on configuring these firewalls.