Jobe Platform, I think.

Yeah... He's on Jobe Platform, in between the teleporters to the Market and the Plaza.

You can warn your friends, and in some cases you can warn your organisation (depending on the org) but you can't use public channels or forums to name & shame people. That's not allowed and, as Snakebite said, could be considered harassment. If you're on someone elses team, ask for them to set /loot...