If there's something that *hasn't* been taxed yet, it won't be long before *someone* finds a way to put a tax on it (take a look at what's been going on in the City of Seattle, Washington, U.S., for example).
Or as Mr. Harrison articulately stated in 1966, "Let me tell you how it will be: There's one for you, nineteen for me. 'Cause I'm the Taxman..." ("Taxman," from the Beatles album "Revolver")
As someone wise once said, "There are only two certainties in life: and those are death and taxes."