Hackers Hijack PC’s for Sex Sites: Hackers are getting control of computers with broadband connections, and installing a little Web server that delivers pornographic banner ads. The user may never notice, and while he or she is writing a letter in Word, their machine is serving up naughty graphics behind-the-scenes.
“‘This system is especially worrisome because they have an end-to-end anonymous system for spamming and running scams,’ he said. ‘It’s not a far stretch to say that people who are running kiddie porn sites could say, “Hey, this is something we could use.”’”
Another view from CNN:
http://www.cnn.com/2003/TECH/internet/07/14/porn.backdoor.reut/index.html