Permit basic account data (e.g. dollar value of all investments) to be collected with a secure third-party aggregator

Many discount brokerage firms, and other personal finance-oriented firms, have an aggregator feature that, once set up, displays and updates financial account values from accounts held by the client at multiple institutions. So, when I log onto Schwab for instance I can see account value for my accounts at Fidelity, Chase bank, Nationwide, Ally Bank, etc, etc.