I usually run 4 shammy while questing and I have helped others that asked to join up until about a week ago. I had a guy join me for a quest and he looted the item (one drop per spawn) dropped group and sent me a tell saying, "sorry many but if you only had one less Shammy I wouldnt have had to do that". It was really no big deal, I had to wait 5 more minutes for the spawn and got the chain done long before he did.

I no longer invite people to my group or assist those that request help. And if someone ever did that to me I would definately go into "grind" mode and kill a few ogre for some exp. That is my story and I am sticking to it!