Hybrid WiFi
This causes a number of problems for owners of the WiFi access point:
1. Contract with ISP says they can't share connection with 3rd party
2. Illegal activities commited on said WiFi
3. Owner of WiFi ends up paying per-GB for excessive usage.
Personally I have a relatively unlimited internet connection. I think it would be good if people were able to offer an unpassworded DMZ on their internet connection (with minimum QoS priority) for guests to use. This would be especially useful in metro areas.