84% people had their PCs infected with spyware in 2004

84% of respondents to The Ponemon Institute survey said their computers have been infected with spyware in 2004. 42% of infected users had "no idea" how the unwanted programs had landed on their computer. 38% attributed the infestation to having downloaded free software, while 8% said a spyware program downloaded automatically when they visited a site. 61% didn't remember consenting to adware, and 97% didn't recall giving permission for spyware.