Deposits and withdrawals really sucks.
- With the 4 digit pin stuff it means you can only have a maximum of 10000 users
- When depositing, if someone mistakes his pin, his money will go deposited to another user if the pin exists
- A malintentioned user could withdraw all user accounts to his respective accounts
BTW, where is the withdraw page ? I couldnt find it
Actually, unlimited users.

Duplicate user names aren't allowed. Duplicate pins don't matter as the user names must me unique and must be entered when submitting an exchange deposit.
Deposits are matched via user name and pin. Unless there are two users with the same name (not possible) and pin (possible, but wouldn't match the name), so only the user with their matching pin can process a withdraw request.
The withdraw page is on the Exchange page with the BIG WITHDRAW BUTTON!
Any other issues?