Like I said, this happens frequently to me on my multiboxing group and rarely when solo. But it happened to a guildie of mine when we were soloing once. This person was too low level for an area and we were headed down the road. They kept asking for assistance and we would have had to gone an additional 10 minutes out of our way, so we kept telling them to petition their fellow guildmates for help.

Instead he just /follows my guildie. My guildie warned him... you do that, you'll die. He never responded. My guildie starts running in circles, etc but the only mobs that come to attack go for my guildie first since he was technically low for the zone but still with my help he was within the parameters needed. So.... my guildie had a brilliant idea. He was a warlock, casted unending breath on himself, ran over to the nearest river and drowned the kid.

I felt bad but at the same time we had politely refused him and he took it upon himself to attach himself to us and go afk. Bad idea...