That initial investment is expected to cover the board's operating expenses for approximately six years or two three-year terms. It will pay for things like office space, staff and travel expenses. Facebook says it plans to continue funding the board's operation after those first six years.

To make sure the funds are properly managed, Facebook created an oversight board trust that will "ensure good governance and accountability." It will be tasked with things like administering payroll, ensuring tax compliance and reviewing the board's annual budget. Facebook expects the trust to have at least three individual trustees, and Brown Brothers Harriman Trust Company of Delaware, N.A., will serve as the corporate trustee.

In response to feedback that the board should be grounded in human rights principles, Facebook also commissioned a third-party Human Rights Impact Review. That will, at least theoretically, help structure the board so that it promotes human rights. Facebook will follow recommendations on things like board member diversity, transparent communication and privacy-protective tools.

There's still work to do, like filling board member positions, but Facebook expects the content oversight board to start hearing cases next year. Who knows what kind of content disputes and regulatory trouble Facebook will have stirred up by then.