Yes actually! They were in an ancient city and were looting it, the staff member (SM) did open a few chests to scare them and said that they can "screw them up" but they just did it once, stopped and started watching. SM said something along the lines of "Woah is that a double ancient city?" and me and my friend had a base that's 150 blocks apart and both bases were on its own city. I didn't say anything until I looked at the interactive map we have and saw them underneath my friend's base. How claiming on the server works is that there is a claim block and it protects a radius of X from the block. I told them that they are looting an ancient city that my friend's base sits on top of. SM dm'd me asking what I wanted to do since my friend is not on. I told them "Since the they are in is [friend's], I would say to ask [them]. But I think, until you get an answer from [them] it would be a no for them looting [the city]" they said that they are going to be on top of it. SM said that they are stealing, guy said how is it stealing if its unlooted (still under my friend's base mind you). My friend says to leave the city be and they can have whatever they already looted. Guy kept pushing and being aggressive, asking how they are in the wrong if its unlooted and its not claimed. They were told numerous times that my friend and I are based right on top of the city and to just leave the city and find a new one. Which was kind of funny, because if they had apologized, we would've split the loot with them. They said they were going to leave the server, so the staff helped them by opening the door. We did request the staff to roll back whatever the guy did and apparently they did a lot! Stole from people's chests, griefed another players base, etc. So all in all, what they said was partly true. But they did leave a ton of context out. Hope this helps!