Brainier networking gear to the rescue. Note the list of evildoers in the opening paragraph:

Networking equipment makers are adding “intelligence” to their gear in an effort to protect bandwidth resources from being hijacked by spammers, denial-of-service attackers and peer-to-peer application users.

[…] Traditionally, Internet Protocol (IP) networks have been built for “best effort,” which means that networking devices are designed to simply pump as much traffic through big pipes of bandwidth as quickly as they can. Ensuring quality of service and implementing security are usually done at the periphery of the network.

But as networks get flooded with millions of unwanted e-mail, peer-to-peer traffic, and denial of service attacks, network operators need tools to control how much traffic comes onto their networks.

“Adding intelligence in the network will cause a lot of these problems to go away,” Christy said. “It’s much more effective to simply control who gets access to the resources.”