Okay but how do you transmit the data between the brokerages and the client?
If your making direct requests to the brokerages network you have to deal with many response codes and different scenarios, rather than if you made your own centralized service with oauth for example.
Not to mention if...
You register another offshore server which sits in-front of your actual server and hides the IP address.
You can also implement further security features on the front server to further protect the real IP.
Send a pm for some more infos.