A report by Donkr.com states that the Entraction Network will ban players from Canada, Israel, Norway, Russia and Turkey effective September 29, 2011. Recently International Game Technology (IGT) acquired Entraction. IGT is a US slot machine manufacturer based in Reno, NV.
IGT manufactures the Game King video poker machine. Game Kings are the most popular video poker machine in the US and are used across the world. They also manufacture many of the most popular slot machine games including Wheel of Fortune. Banning Canada is a bit of a mystery. The only assumption I can make is that since some Canadian Provinces have started their own lottery based online poker rooms IGT may have thought competing against the government there was not a good idea. Israel, Russia, Turkey and Norway have processing or other laws against online poker.
IGT bought Entraction to diversify their holdings. I feel certain they also wanted to be ready in case US regulations are passed. This way they own online poker software and if US players were not ringfenced, IGT would already have a player pool to send US players. IGT likely wants make sure that they are 100% legal going into possible online poker regulation in the US. When I find more information I will post it.