I am posting this in a new post as the original one is getting quite long. Lots of folks don't think it will be possible to grief other players using the new Justice System. I would like to describe an easy, and probably unpreventable, way to do it.
Point: There is NO targeting in ESO. Everything is AoE of one sort or another. This is an important basic mechanic of ESO and unlikely to change.
1. Head into a heavily populated banking area. Or any heavily populated area, like a market.
2. The griefing team (and this will be done by a team of six to ten VR12 players) starts laying down just a load of AoE damage. They take out any guards that happen along and all the other killable NPCs. They cause all NPC interactions to break.
3. Other players decide to join in and 'teach the griefers a lesson!'
4. Other players start throwing around attacks, and since the crucial NPCs are not actually dead, they are hit by the anti-griefers AoE hostile spells.
5. Other players are flagged now; they die and are penalized.
6. Or, they could flag themselves as 'Guards' and be immediately destroyed by the griefing team.
For you folks that think that human behavior is basically good and that people will 'play nice', I reference you to the Stanford Experiment.