http://3i3tiafgjecjzo6bbmfxbxg2sha2i3wa4db3p64tc5kycd7qd6gdyxid.onion/bitcoin_guide
It's a protection against money laundering. When you withdraw funds from exchange, you enter destination BTC address which is just an address. The seller doesn't know who you are and the exchange doesn't know whom you are sending bitcoins.
19 similar results skipped