The main idea to play an MMO is to take a role and create a character in game - so indirectly all people are roleplaying a character to distance themselves from real life to a game, which is simply a game for most players in any MMO communities. So why are people afraid of gankers in fantasy worlds like ESO and other worlds in the past like the old Ultima Online, or EvE online to create factions to limit their MMO possibilities?
It seems that most AAA roleplaying games in an MMO like Swtor or ESO avoids open world conflicts and political struggles within their own borders.
Ultima Online and Age of Conan had a poor system to handle gankers in general, and same had Shadowbane with a few safezones. Although, it was a great player driven MMO setting with old guilds who battled amongst eachother
in new campaigns that lasted for 8 years before UBI closed the door. When you found a decent guild in Shadowbane or old Ultima Online a ganker ain't a problem, but it's more fun, or like a challenge when you're used
to open PvP worlds like Darkfall and soon Unholy Wars.
So what could ESO have done to avoid factions alltogether, and to implement more an open world PvP driven with similar plots you see in Skyrim or in ESO that different provinces fought for power, or greed, perhaps political reasons to claim the new Emperor of Tamriel.
A ganker in Skyrim could sit in prison in like 5 hours in game if he got caught and they had a decent laws to balance such behaviours. And a typical ganker would think how to exploit the system like laws.
I won't sit in prison for 5 hours, because I got caught murder someone so I will create a new character in a different land and start ganking, but they had similar laws in other provinces
of Tamriel as well. So it ain't that easy to exploit unless a ganker create a lot of characters when their lockpick is broken trying to escape prison in old fashion Skyrim style..
Well, just a few personal opinions how great this game could have been with other methods how to develop an exciting MMO, which is actually a challenge and you feel -
dangers exploring the wild, and outskirts of major cities in Tamriel.

Look at what happened with Aion, for example. A game that started out with open world pvp and then later on had to give buffs on their servers to protect players from gankers. Open world PvP pretty much killed the game. People don't like to be ganked.

If they have open world PvP, they will have to include the option for players to turn the PvP flag off. Otherwise they run the risk of alienating a large portion of the MMO crowd.

I much prefer the idea of them limiting PvP to Cyrodiil.

But if I have to choose between not being able to explore the other faction maps at all and being flagged for PvP only when in other player faction maps, I might consider it. Your home faction maps should not flag you as PvP regardless. Those zones should always be safe.

Of course PvP on UO was all about avoiding getting ganked or ganking the gankers but at least it was fun becaue in that game when you killed someone you got your instant reward by looting their pack. And if they were silly enough to be carrying their house key you could loot it and use the key to gate to their house and loot it too.

However you quickly learned that you carried crafted gear only and always had at least one spare set of gear in your bank in case you got ganked and needed to suit back up fast and go find the ganker and kill him to get your stuff back. It was fun, because then at least endgame had a purpose and you did not have to gank every player, instead you could be a player who hunted gankers...it was fun edge of your seat heart poinding PvP because there were REAL consequences for being dead, not the Ho hum I am dead but didn't loose a thing feeling of MMO's today...