Tyrannical treatment of American citizens

Quote from the morning from Glenn Greenwald:

There is, of course, no moral difference between subjecting citizens and non-citizens to abusive or tyrannical treatment.  But as a practical matter, the dangers intensify when the denial of rights is aimed at a government's own population.  The ultimate check on any government is its own citizenry; vesting political leaders with oppressive domestic authority uniquely empowers them to avoid accountability and deter dissent.  It's one thing for a government to spy on other countries (as virtually every nation does); it's another thing entirely for them to direct its surveillance apparatus inward and spy on its own citizens.  Alarming assaults on basic rights become all the more alarming when the focus shifts to the domestic arena.