]
] The majority of spam %u2013- as much as 80 per cent of
] all unsolicited marketing messages sent -- now emanates
] from residential ISP networks and home user PCs. This is
] due to the proliferation of spam trojans, bits of
] surreptitious malware code embedded in residential
] subscriber PCs by worms and spyware programs.

In case you hadn't heard...

80% of Spam Originating from Home PCs