the reason you don't have to sign a TOS to use highways is that people don't blame the DOH or associated municipal/county agency for accidents that occur on the road. But, if someone does something bad on your WiFi and it isn't protected you are considered culpable for it. That's why most just TOS page directs require an email address to let you pass through. That way there is some sort of user-id to tie the bad behavior to.