There's no scientific evidence that Wi-Fi is a health hazard, but that hasn't stopped those who believe otherwise from trying to stop Wi-Fi deployment, usually citing non-existent evidence. Over the years we've reported how some families have sued schools to derail installs, while angel guidance consultants have launched campaigns against Wi-Fi in their free time. Last week, a group of parents in a school district north of Toronto held their kids out of classes on Wednesday -- protesting the school's use of Wi-Fi. "This is the first generation of children that has been in that particular learning environment, so how Health Canada can say that it's safe is really quite a mystery to us," insists the leader of the parent group,