[amelius]

The FBI could set up a website where you can check whether your Bitcoins were involved in some crime.

This would set up an interesting experiment. Would you accept a $20 dollar bill in the supermarket if you knew it was used in some ransom case? And what if suddenly you knew you owned such a $20 dollar bill? Would you try to get rid of it as quickly as possible?

[diab0lic]

Does the bill’s involvement in a ransom reduce the value of the bill or implicate me in any way? I’ve never considered someone morally responsible for the provenance of their money outside their control. Maybe I’m missing the point.

[amelius]

Well, the FBI could make it illegal to own Bitcoins that can be traced to criminal activity.

[miohtama]

2% of money on bank accounts have been involved in some crime.

What would you set as a threshold?

[amelius]

I'd invalidate that 2%.

[CRConrad]

That's exactly as stupid as invalidating, say, a 20€ note that I got in change from paying a taxi ride, and the driver received in good faith from some crook who took a ride with him before me. By "invalidating" it, you're robbing me of the worth of that note, those 20€, even though I had nothing to do with that crook.