It's illegal Wi-Fi hopper, to use other people's open network (and to run an open network I think)
Plus what if someone used your network to watch a youtube UK people are not allowed to see? They you get in trouble with big brother.
Also your plan would be technologically complex, to get unity and to prevent clogging (how do you limit flooding one person's network), etcetera.
Also; france doesn't like freedom any more, they elect bush lovers and create fascist laws against internet users.


and we'll get started.

http://www.theinquirer.net/gb/inquirer/news/2008/07/26/bostoon-spat-bt-wayleaves

There are about 4700 people living per km^2. If just a small fraction of them open their Wi-Fi access points, add a little bit of software and build up a network with their neighbours, the entire city would be covered in no time. With a little bit of effort you can bridge distances of a few km. Connect the London net with Northhampton, Cambridge, Southhampton, etc. all the way up to Norwick, and you have the entire country covered with a supplementary Internet, for free. Next, liberate France.