You are missing the point
The whole basis of Bitcoin is that it is virtual, untraceable and unattributable. There is deliberately no trace. Its not a flaw, its a design axiom.
It not like cash, or credit cards or PayPal. Its more like barer bonds - the person with the bond has tottal title to it. If you had a bond that you bought for 10,000 and it became worth 500,000, would you keep it in full view on the table next to your open front door? Probably not. You might pt it in a safe deposit box, because that way you can keep it but still not declare it for tax. Thieves can still break in, but its harder to do.
The point here is that no-one can prove he did have the money in the first place, and no-one can show who has it now (assuming it has been stolen). That is what untraceable means.
For anyone else who does not understand this, as has been said previously, go read Cryptonomicon.
Mines the one with the barer bonds in the pocket.