Let's take the late 20's for example, when the mafia, bootlegging and politics were hot. There was no camera around to record crime, it was all he said, she said. If someone did you wrong, you took matters into your own hand, you didn't think twice about what could happen if you got caught. To you, justice was taken into your own hands and you didn't worry about the law. You went after the person that pissed you off or got in your way. Crime was not really reported or taken in to affect back then. With out the advanced technology it was easy to get away with a lot.
Now take present day, we are so plugged into every piece of technology and have access to the internet at our fingertips you can barley look at someone the wrong way without it going viral. Besides having the fast source of getting information out, we also have television reporters, newspapers, magazines, etc. Just as much power that the social media has on such a topic, it can easily do the opposite and keep it quiet. Something can go unreported and not talked about if the government wants it that way. This has played a huge factor when talking about justice. You can easily get the correct amount of information needed to put someone away, versus going and taking matters into your own hands.
To me, justice has drastically changed and i think technology has a big part in it!