Cannot brokers just steal interests belonging to other brokers that are listed on the platform and work them themselves?
No, Broker passwords allow brokers to see only those interests that are being worked by their brokerage house. Trader passwords allow traders to see all “activated” interests along with the brokerage house that is responsible for the interest. However, all passwords are strictly controlled by BrokerHub which monitors there use by various measures including an IP address monitoring system. If a trader tells their favourite broker which brokerage house is working what, then this is a fault of the trader and not the system.