Quoteif the vendor was smart, they would not sell bitcoin from the same account they sell drugs.This is pretty much a given, but even if not it would make no real difference. If Law Enforcement somewhere actually had a vendor account they might cross-check an order name against their registry and hope they get lucky, but the act of laundering Bitcoin in itself would be on such a small scale it would be an enormous waste of time even if they catch someone red-handed (unless you mean they might get a warrant for the address with that basis alone searching for drugs, which won't happen - yet atleast).Now granted police don't act on logic or what's necessarily best for society, but as far as I'm aware there has not been a single case with proof there has been a Law Enforcement Vendor on Silk Road. I personally think this is due to the simple fact there's a vendor fee. For them to actually register a real vendor account they would have to go through a lot of bureaucratic procedures which probably are on par with if they were to sell real drugs to someone, might happen in hardcore cases but no vendor on Silk Road is big enough to warrant this.Another aspect is I think people overestimate Law Enforcement to a high degree, they work best with systems they've known for a very long time and are very slow to adapt to technological advances. When was the last time anyone heard police cracking a PGP identity, or any kind of encryption for that matter?