TyrannyOfTheMajorityStakeholder is the exercise of control by a powerful project stakeholder.  It can be the person controlling the budget for the project, a politically powerful stakeholder with connections, or a project leader who thinks he/she knows best.  The tyrant can often include all the stakeholders, only to discard their contributions because they think they know better or just want control.  TyrannyOfTheMajorityStakeholder is occasionally a cause of project requirements or schedule slipups.
-- DionHinchcliffe