I take $100 out of an ATM in $20 bills. The ATM has recorded those serial numbers. I immediately get mugged. I identify the mugger to the police. The money is seized. The twenty dollar bills are identified as those I withdrew from the ATM. The mugger gets tried, convicted, goes to jail or gets counseling (liberals) and I get my $20 bills back.
You are apparently not sober.
If you had any common sense you would recognize that this example is unrealistic. In the real world, the mugger will not be caught immediately, but spend those bills before he gets caught.
Not sure about US law (maybe D&T can comment?), but German law is crystal clear on that. If someone accepts money in good faith (as part of a legal transaction) then he owns that money. It is not possible to legally acquire stolen goods, but money is an exception (§935 BGB).
Without such a provision, trade would not be possible. Any grocer would have to fear that, at some point, the police seizes some of his money because the mugger said he bought some groceries at that store, using the stolen money.
BTC has to be the same way, or it is not electronic cash. No one, absolutely fucking no one would accept BTC anymore, since he could never be sure whether some of that BTC is tainted and gets seized or redlisted later on.
But I have a feeling you know this already, who is paying you for promoting redlisting?
No one. I put half my IRA into Bitcoin a year ago. I kept one third at MtGox. I have never bought anything illegal with a Bitcoin or fraction thereof. I registered my MtGox acount with fincen. I have nothing to fear from scrutiny. Criminals do.
Tho I can understand not wanting exposure about one's life or finances. A member of the family sat on a federal grand jury that indicted a very powerful political boss many years ago. One learns there is nothing that can be hidden from their minions. All politics are local was said by a former speaker of the house.