How does a farmer know what your level is. We had a small hunting group (three characters) in Wall of Argos the other day. We had a small room to ourselves for a while and it was going pretty well. Then some farmers from an adjacent area came into the area where we were. They started KSing so we flagged on them and asked them to leave.
Then the lead farmer said "your level 68" to the Destroyer who was flagging on them. He was right. How did he know that?
They are using a third party program which is giving them that type of information. What i would do is to take down their names and fill out a game peition. And state the details as you post here in that, so the GM staff can look into the issue and see if they can catch them in the act.