BBC News – Web economy in G20 set to double by 2016, Google says:

This isn’t surprising. How much of the money made by people all over the globe through online commerce is declared to the tax man? A relatively small percentage of the total, I would bet. Also, the web is the one area of the ‘legal’ economy with the least government intervention and restrictions. Government ‘run’ economies crumbling, the web economy growing rapidly. Empirical evidence to back up the (long-standing) rational economic arguments against government control or intervention in the economic affairs of individuals.