Look at the actual charges in the indictment. All the BTC-e stuff is not what he's charged with. He's charged with transferring stolen Mt Gox Bitcoins to Tradehill, a San Francisco based exchange (now defunct). That's the US connection that will seal his extradition.
They also allege that BTC-e is (at least partially) hosted in the US and does business with many US companies, which is likely true. But that's not what they charged him with. Maybe that will come later after he's extradited and they have a chance to go through the evidence they no doubt collected when they arrested him.
On an unrelated note, it looks like the traceability of Bitcoin transactions played a major role in this. It turns out that Bitcoin is really not a great way to launder money, unless you want a record of your money laundering archived forever, redundantly, on a distributed system of computers around the world! I expect future crypto-locker viruses to switch to Monero instead of Bitcoin now that they can no longer cash out through BTC-e. Subsequently I expect to see Monero delisted from any exchange that follows KYC after some pressure from law enforcement.
They also allege that BTC-e is (at least partially) hosted in the US and does business with many US companies, which is likely true. But that's not what they charged him with. Maybe that will come later after he's extradited and they have a chance to go through the evidence they no doubt collected when they arrested him.
On an unrelated note, it looks like the traceability of Bitcoin transactions played a major role in this. It turns out that Bitcoin is really not a great way to launder money, unless you want a record of your money laundering archived forever, redundantly, on a distributed system of computers around the world! I expect future crypto-locker viruses to switch to Monero instead of Bitcoin now that they can no longer cash out through BTC-e. Subsequently I expect to see Monero delisted from any exchange that follows KYC after some pressure from law enforcement.