Things NOT to do in a WoW Instance.

Things not to do in a WoW instance without checking with the group first:

• Run off on your own
  
• Target new things that haven't gone aggressive yet
• Open chests without getting the roll
• Rolling for a "Bind on Pickup" item that doesn't work with your class.

Just to name a few.

I had one guy in my party be guilty of the first two and got me killed twice.