Linked accounts can only send orders or modify orders in the brokerage account. Linked accounts also receive account balances and positions. Any other operation, e.g. money transfers, or account changes, are not possible from Portfolio123 and must be done on the broker's website.
In addition we've added other layers of protection for other types of breaches. When you have linked accounts you are required to use Two-Factor Verification. In the unlikely event of an internal breach to our servers, we have also encrypted all sensitive information like passwords and brokerage account numbers.