This topic needs to be sorted out in much finer detail. Where are the fine lines that constitute the difference between griefing from fair game play? Should certain actions, techniques, and builds be banned from game play? What should be considered a “reportable” offense, and what falls under free speech? How severely should players be subjected to moderation? What actions should justify developer interference? What is the most effective method for bringing questionable actions to the attention of a moderator for judgement? And in the case of a player being found guilty of griefing, cheating, hacking, or using exploits, what manner of punishment should be utilized? How much influence should the typical player have over another players behavior in game?
I think we badly need some sort of in-game message or mail system, so we can at least try to work things out ourselves 
In the event that a player is uncooperative, then what? Player diplomacy often leads to increased hostility and tends to feed trolls.
Ideally a game should prevent as much griefing as possible by its mechanics.
(Like lava not flowing out of your own plots would prevent lava griefing.)
This is where we should spend our creative power.
I not sure if it’s neccesary to redefine griefing or the limits of freedom of speech. This has already been done countless times:
I still think we need the ability to directly ask someone why they did something. If they respond with hostility, then we can deal with it as appropriate. But there’s too much room in a sandbox game for really simple misunderstandings or “can you move that one plot” kind of things.
Hey Havok 
Thanks for starting this topic 
I’m all for players resolving their issues on their own but this is not the topic here.
As for me I’m all for being very aggressive in restricting players from doing harm to others. By this I mean that even the slightest glimpse of offensive behavior should be slammed with a hammer, not a ban hammer, but still regulated.
The main issue here is that I see here is players not being happy about people building around their build and covering certain nice angle views of their build. For this kind of cases I’d just leave them be, if you don’t want to have your build covered you need to claim enough space around your build so that it can shine as you would like to. Of course to every rule there is exception, if player A completely surrounds player B’s build and there is record of malicious intent (chat screenshots, moderator asking player A what’s it about etc) than it should be sanctioned.
This is also considering roads and such, where city builders need to claim all the stuff beforehand if they don’t want their plans obstructed. If you want a road that will stretch 100 plots, you need to claim all of those. I don’t think it is fair to put burden on moderators to resolve such issues.
Another category of disputes is player A taking advantage of permissions given to him by player B on a beacon. I don’t think there is a case for considering this griefing no matter what are the circumstances, it only your responsibility to whom you grant permissions.
Another case is when player “tags” other player’s build with a word that is negative in any way. For this to be considered griefing there should be nothing between “tag” and build, and they should be close enough so that it’s obvious that it was meant as an insult. I would show 0 tolerance for such behavior.
I’d just add that in all cases of griefing, whatever it might be considered in the end, griefer should be contacted and there should be fact checking done to clear all misunderstandings. Everyone should have a chance to explain themselves. But I guess that is understood without saying
This should be enough to get the discussion started, what do you think?