In Germany, there is http://freifunk.net/en/ (the English wepage is a bit sparse) which has the capabilities to do mesh networking where nodes are dense enough. Since this is rarely the case, it's a great way for people to share their internet connections with the world without taking on any liability. All Freifunk data is routed through their VPN, and they are registered as a provider, so they're not liable under Störerhaftung.