“The spokesperson says the approximately 26,000 Bitcoins seized are just the ones that were held in Silk Road accounts. In other words, it’s Silk Road users’ Bitcoin. The FBI has not been able to get to Ulbricht’s personal Bitcoin yet. ‘That’s like another $80 million worth,’ she said, explaining that it was held separately and is encrypted. If that is indeed what he’s holding, that’s close to 600,000 Bitcoin all together or about 5% of all Bitcoin currently in existence. Thanks to the transparency of the Bitcoin block chain, Reddit has located what looks to be the FBI’s Bitcoin wallet; there’s an influx of 27,000 Bitcoins into it starting on Wednesday, October 2.”
http://www.forbes.com/sites/kashmirhill/2013/10/04/fbi-silk-road-bitcoin-seizure/