Can they not only seize if they confiscate the pc/hardware? what if the back up was placed on to the cloud and a transaction was made on another pc?
They already moved them (so they have the keys). Some are here:
http://blockchain.info/address/1F1tAaz5x1HUXrCNLbtMDqcw6o5GNn4xqX
The rest are here:
https://blockchain.info/address/1FfmbHfnpaZjKFvyi1okTjJJusN455paPH
So, by moving the coins and consolidating them they have been shown to own them.
This may not be all of them but it is the BTC that the FBI has found so far.
Holy crap the FBI has a lot.
If they sell the btc at market price right now, it will surely pay them back for the expenses of the investigation.
And then some... Probably the expenses for the whole year!
I know.. seriously, FBI made bank busting Silk Road!
The government should use the money to pay for its debts though, it has too much...