WiFi and the children

CNET has an article about some concerns arising around ubiquitous WiFi and children's access to the Internet. There's no mention of libraries or what they went through, but it will be interesting to see if cities that are providing open WiFi will face some of the challenges that libraries did. And if not, why not? Isn't ubiquitous, open WiFi Internet access the "worst case scenario" for those who so hotly opposed open Internet access in libraries?

I see that some libraries that offer WiFi are only allowing WiFi access to "older" children. Loudoun County, VA, has a rule: "Patrons age 17 and under must have a parent or guardian sign the necessary forms." Others, like Lansing Public Library, are making their WiFi entirely open: "Our wireless Internet access is open to patrons of all ages; parents or guardians of children under the age of 18 are responsible for supervising and guaranteeing their child's proper and safe use of the Internet." This brings up all kinds of interesting questions in my mind about the differences between accessing the Internet via the library's computer stations and accessing it from your own laptop. Is the obligation to protect children related to who provides the hardware? Are schools providing wireless, and if so are they using filters?