Sigh. Probably not enough screens but here goes.
During the Stronghold test a guy, Raven_Phama , suddenly started attacking and destroying the different buildings I had set up. I asked him over chat to stop it but he kept doing it. After every time I tried to find him, but he stopped doing it so I didn't get any screenshots. Shortly after a friend of his (Raven_Khanship) joined and they behaved for some time. (by "behave" I mean they stood at dummy and punched each other).
Then they started doing it again and me and some other players were so fed up with it we tried to get an admin. This led to them teamattacking and killing.
In total they managed to destroy about 7-8 different workshops and one wall.
A poll was sent up on one of them, which made them stop. One of them said sorry and left while the other (the one polled) remained, long enough for the poll to pass and he to be kicked.
Here is the screen of the log that I took.
In the picture you can see two teamkills bu Raven_Khanship and three different people wanting to stop them/contact an admin. VRN_Shazbot was one but he didn't do anything even though I reported it multiple times (I chat to admin).
For the record. It was mainly Phama that griefed. As mentioned before, he stopped for some time when Khanship entered, but continued shortly after. What I saw of Khanship was that he attacked people when they were fighting Phama, so I'm not sure if he was actively teamattacking or just helping his friend out. No matter what, he still tk'ed, but the big griefer here was Phama. Khanship was also the one who first stopped (and probably made Phama stop) and who said sorry.
There was also someone who mentioned that they would back this up, please do so if you read this thread.
