> "but its not like they won't just upload that data once you flip wifi back on..."
Only if gateway is up. I can't really control a mobile phone loaded with a corpotate OS (I guess this is the point the replies are trying to make), but I can significantly control a router loaded with an OS I edited, compiled and installed myself. I have found that I can reliably keep a mobile phone from getting access to the internet when it is relying on me provding the internet access.