In 2008, New York State passed a law that would force online retailers to collect sales taxes on shipments to state residents, PA was Feb 2012... where have ya'll been haha
Last May the stupid brazilian government forced Amazon.com to collect over 90% of taxes during the checkout - Before that, you could be charged or not, it really was out of luck, but even so it was "only" 65% of the value.
Now I only buy books from Amazon - those can't be charged for extra taxes - and my other stuff, from Europe.