When the feds arrested ulbricht, and took over the silk road site. they were able to seize all 26000 bitcoins found in the personal wallet of ulbricht. and they tranfered it into their account. but since the bitcoin transiction can be tracked publicly. users finally find the wallet address of FBI. and they took over to transfer the bitcoins to FBI’s wallet by adding comments.as tag to the wallet address as ‘Silkroad Seized Coins’ the comments can be seen from the screenshot below, which comes in block chain of FBI. The Authorities having access to the wallet of ulbricht, did not helped them and that cant be used. since they still need the private key to bypass the Authorization. The bitcoins taken as part of the silk Road operation will be held untill legal proceedings have finished, then they will be liquidated, according to a FBI spokesman.But how far is that true no one knows, they can surely spend it in their operations and funds.