My SBC Coin is a web-based interface that allows you to use SBC Coin without running a full SBC Coin node. However, because this convenience comes at a cost: it is extremely difficult for My SBC Coin to securely deliver its code to your browser. This means that there is considerable risk in using My SBC Coin for large amounts!
It is recommended that you treat My SBC Coin as you would treat your actual wallet, and not store very large amounts in it. For long-term storage of SBC Coin you should create a cold wallet using SBC Coin address or similar.