Comment Re:Population density is a plausible cause. (Score 1) 274
The article says that the USA as a whole has a lower use of secured AP. So unless there are huge numbers of unsecured APs in the rural areas of America, the large cities (with their secured APs according to this theory) will swamp the results, yet that doesn't seem to have happened. Therefore I think population density isn't the major factor, and this is bore out by the fact that Sweden and Norway (countries with low density) can come higher than higher density countries.
The densities for the larger European countries are ordered: Netherlands, Belgium, UK, Germany. While those countries were high on the list, it cannot be all there is too it as Spain comes top.