coinbase has the decryption keys to the wallet, so they have full control over the currency. users of coinbase never "owned" or "have" anything. You gave money

coinbase has the decryption keys to the wallet, so they have full control over the currency. users of coinbase never "owned" or "have" anything. You gave money to coinbase, they have the money now. If you had the decryption key offline, then you could control the cryptocurrency. this is cryptocurrency 101 - the very basic nature of the blockchain itself guarantees whoever has the key to have ultimate control. Coinbase is not a bank, they don't have to give you anything.