Yeah that's fair comment, but let's remember that those put into the Colosseum were basically enemies of the State (i.e., Christians) and certainly not Roman citizens. As I said, if you paid your taxes, worshipped the right gods and kept your long aquiline Roman nose clean, in essence the senate left you alone. Certainly there was infighting among the noble houses, but in terms of being oppressed by your own government as a normal, law-abiding citizen, I don't think it really happened.
I suppose you could maybe see Castro as one too, though of course he crushed his enemies, but then, gotta crush something, ya know?