Is there a specific clan chat you all use?
If we were all in the same CC Jagex would come and ban us all -.-
They can't ban you for using Sythe... They can only ban you for real world trading.
This. Even though I know there's not a huge chance of getting banned, I personally wouldn't risk one of my accounts by joining an in game cc. Talking with everyone on the forums is good enough for mePeople are usually too scared to join a chat where 'cheaters' are. They don't want to risk a ban, but we've attempted to have one of these in the past and didn't work out.

