1) protect non griefers from griefers
2) do so avoiding false positives (we don't want people being prevented to play under false assumtions of griefing)
3) make that the cure is not worse than the disease, especially for the potential victim ("just let the griefer go and revert to a previous save" is NOT a good answer)
4) also make it that the solution is maintainable and resilient (so that it can be used as long as there will be people playing Factorio)
This is more a brainstorming topic than anything else.
You can't spot a griefer before he has done some griefing. Once the griefer has been spotted and identified as such, what solutions can be provided to the community to protect itself from that griefer again ? Every solution that has been suggested here so far has advantages and drawbacks.
I admit I personnally don't really care : I am that kind of people who doesn't like multiplayer because I don't like people in general. Call me misanthrope if you feel so, you're probably not THAT wrong. I *might* play occasionnally multiplayer, only with long lasting friends I personnally know, but will never connect randomly to public servers to meet people. That way, if that friend does some griefing, I know where he lives, I get at his home, and I break his fingers, which should prevent any further griefing
![Twisted Evil :twisted:](./images/smilies/icon_twisted.gif)
So I don't speak for me, but for players who deserve the best online experience with Factorio.