Many non-profits have elections for board positions where members of the organization or its community can help determine board membership and vote out bad directors. Mozilla Foundation's by-laws (http://static.mozilla.com/foundation/documents/mf-bylaws.pdf) states "This Foundation shall have no members" (Article II).
Existing directors are the only ones who can vote in board elections. They are only accountable to themselves.
Mozilla Corporation is a wholly owned subsidiary of the Foundation, meaning all voting shares are controlled by the Foundation's board.
I find this to generally be a dangerous structure for a non-profit to have. Think twice about donating to any charity where the directors are well compensated and accountable to no one.
If the board is stubborn there is nothing anyone can do to force them out. Hopefully with pressure the community can achieve some reforms. One I would push for immediately is adopting new by-laws that allow community involvement in board elections.