Bitcoin transactions are visible/traceable, but doesn't mean you can match txn to identities.
If there is one address in the middle of you paying somebody, and that address was generated either offline or through Tor, there's no way to prove you own that address unless somebody can extract the private keys from your seized hardware and match it up to the public address.
Transactions don't prove anything, anyways. If you sell on localbitcoins or IRC, you have no idea that the anon guy who showed up to buy them with untraceable cash isn't directly 3rd party funding his Silk Rd account. If you look at the blockchain it would appear I paid into SR directly however I sold coins to some random guy I'll never see again, who's contact info I also don't have. Since I sell under my countries $10k cash transaction limit I don't need to take ID or retain contact info. Tracing that transaction proves nothing.
I also can't recall any of the major bitcoin heists being recovered. Only one exchange (mtgox) has a history of holding transactions for ID if they appear to be stolen coins, and they've only done it twice: first time was cleared up with ID, second time they're still holding the coins (bitcoinica/linode theft). Every other bitcoin heist you've heard of through the years the trace leads to nowhere.
If there is one address in the middle of you paying somebody, and that address was generated either offline or through Tor, there's no way to prove you own that address unless somebody can extract the private keys from your seized hardware and match it up to the public address.
Transactions don't prove anything, anyways. If you sell on localbitcoins or IRC, you have no idea that the anon guy who showed up to buy them with untraceable cash isn't directly 3rd party funding his Silk Rd account. If you look at the blockchain it would appear I paid into SR directly however I sold coins to some random guy I'll never see again, who's contact info I also don't have. Since I sell under my countries $10k cash transaction limit I don't need to take ID or retain contact info. Tracing that transaction proves nothing.
I also can't recall any of the major bitcoin heists being recovered. Only one exchange (mtgox) has a history of holding transactions for ID if they appear to be stolen coins, and they've only done it twice: first time was cleared up with ID, second time they're still holding the coins (bitcoinica/linode theft). Every other bitcoin heist you've heard of through the years the trace leads to nowhere.