I have a few examples i'd like to discuss depending on whose still interested in ol' Miner Joe BoB;
A) lets say for example that I want a monopoly on a particular mineral, Iron lets say, and when I go to mine it, I find Miner Joe in the same place. Do you feel it would be fair game to Kill him / Hire an assassin to make sure that he doesn't try to get my Iron so that I can maintain my monopoly? Because this kind of situation may be seen as griefing as I'm not doing this for an actively evil reason, I just want to make my money and maintain control of my income.
This could also be viewed as a one time thing, since once I kill the unarmed miner, he may get the idea to not to go there.
B) Lets say that someone else thats this approach and the assassin is hired to keep killing him if he comes there, would the assassin be in violation of griefing? His contract is clearly telling him that the miner must be killed if he comes to the mine. Not to mention, the contract isn't targeting miner Joe out of the mine, simply in this place as to protect an asset, so would this mean that the employer is griefing?
I feel like that either of these scenarios are going to be quite consistent during the game as its a valid strategy to keep your own assets in check, and everyone has a price (especially in a game where you can be anything you want)