So far of all the answers this seems to be the only relevant one: > And one little privacy issue: what targeted ads display can give out information about you

So far of all the answers this seems to be the only relevant one: > And one little privacy issue: what targeted ads display can give out information about you that you don't want made public to people who may see your screen. The example of the pregnant girl who began getting coupons for stuff for new mothers while hiding from her family that she's pregnant has been mentioned on this page.