Why on earth there are so many people on this thread that think OP was speaking about avoiding taxes? He was talking about an idea of
automatizing them. But imho this is just oversimplified view on taxes.
OP definitely is onto something but paying taxes based automatically based on transactions isn't really the way. I mean if that would be a good way to do it we would now pay our taxes just from fiat money transactions.
Point from Cnut237 for example was good:
Nice idea, but I think this overlooks the fact that (ideally) taxation needs to be progressive.
If say everything is taxed at a flat 20%, then someone on the breadline pays the same percentage tax as a billionaire.
You also have the issue of determining what is income (and how money in is balanced against money out), what is profit, etc.