In theory the regulators, as part of the government, serve the will of the people. But the state under capitalism serves no one but the massive corporations which these regulators are meant to govern. So we end up with fossil fuel guys running the EPA and Verizon lawyers running the FCC.
There is no one to regulate the regulators because the state in its entirety is isolated from accountability to the public.
There is no one to regulate the regulators because the state in its entirety is isolated from accountability to the public.