Interesting -- According to a UK study, demograpghics are skewing for home users, with older people buying a larger percentage of home infosec products (AV, etc.) and younger people being the ones that naively assume they're OK.  Without the data it's hard to analyze further.  I hope that the shift is due to more existing home PC users taking security seriously, as opposed to merely a shift in who is buying PCs. 

"It is thought that 40% of those buying home net security programs are retired.  For the last three years, that has gone up by an average of 13.2%.  But more retired women (53%) were buying security software than retired men."

BBC NEWS | Technology | More women turn to net security