Taxes
There was perhaps no greater burden to a normal citizen than the extreme taxes they were forced to pay. of course the taxes were going towards the roman empire community and not into the ruler's pockets, but the amount of taxes was very high. All the taxes go to the trading networks, the military, new buildings, and other things we use in their everyday lives like the public baths and roads. Kind of sounds like our times, but believe it, that the punishment of not paying taxes can be very dangerous, like sentencing someone to death by fighting in gladiator combats.