While questing in Lonelywood, I saw someone post in Zone chat: "If you're questing in instance 9, switch instances so that we can fit more HE farmers." I didn't even bother checking my instance number. I simply kept on with my quests and then left for Bryn Shander.
On the one hand, I suppose there's no harm in asking people to leave. On the other, I'm not sure why anyone would obey.