Thanks for the explanations, they've broadened my viewpoint on the matter.
FWIW, I never said it was easy. I also never said I didn't want additional punishment on the crime. I do; and in addition to jail time. That way you hurt the criminals where it hurts. If the BSA, RIAA, MPAA can claim missed income with ludicrous amounts, why can't the tax departments? Oh wait, reading the article, they did, and apparently that is just 100% + interest. For maximum efficiency, go after the big fish _first_. But there's so much fish slipping through with regards to BSA, MPAA, RIAA, and also (corporate) income tax. Tech can help us here, but the legal system is flooded as it is. In practice there's out of court settlements which is less ideal since it creates a shadow justice system.
Now, if we do what you suggest, abolish income tax, VAT will go up due to loss of income from income tax, and the state needs income from somewhere. However the effective income of the consumer would go up as well which I forgot. Since there's so much corporate income tax evasion, the consumer and honest businessmen end up with a net advantage of purchasing power compared to the current situation, and we save money/time/lawyers/experts. Although I suppose some lawyers/experts lawyers need to respecialize.
A caveat is that we must implement it on a global scale. Else the VAT is higher in certain countries, while lower in other, which increases the incentive for fraud (buy by proxy). Also, it is too bad it won't work with any of the progressive tax systems. Which is what we in Europe have (YMMV). We could however, while abolishing income tax, move the weight of the progressive income tax to VAT, but what's gonna happen then? With physical items people would end up buying items for others. But like you said it is difficult on a large scale, and for something like a car that wouldn't work very well, since its pretty much bound to a driver's license and its movement is tracked via GPS. With items bound via DRM or service w/o resale value, there's no problem either. In other words, progressive VAT on service would work.
There's also the side effect that people sit on their money. If they spend it, it is (more) heavily taxed. I think that is going to create a massive black market, but perhaps that could be tackled in the 21st century. My main beef with your point is that you believe people are gonna keep getting away with it. I disagree. I believe technology is going to force^H^H^H^H^H us, on the longer run, more honest. But if we were to swap to a progressive VAT-only system we'd also be able to use tech.
EDIT PS: A way to avoid progressive VAT problem would be to rescale incomes. Well... yeah... I just don't see that happening...