I recorded and sent a ticket for one, but can't be doing this every time you meet one, massive time sink for every report, we need active GMs looking around in-game.
My friends and I stopped reporting abusers due to nothing being done about them and because we do not want to spare the time for it any longer. It takes no genius to visit the Lepharist Bastion in Eltnen and list the names of characers who farm there all day long for a whole week day and night.
On top of that the game is full of glitches which make people shout hacks very hastily. For example rubber banding back to a jumped off cliff after falling or randomly targeting characters hundreds of meters away upon ressurecting at a kisk.
If Gameforge wants me and others to report such players with proof again, aka doing the service we pay Gameforge for, they should offer an incentive. I am sure many players would be willing to invest time if they get something in return. For example two hours of Siel's Favour for every report that turns out valid and an actual report to each incident on why or why not it was valid (just an example).
Also NcSoft should add the chat filter as part of the GUI so every player knows about it and every player can customise it easily.