"Going Offline Alongside each list, you'll notice a green switch; when you turn off the switch, you'll be logging off of Chat for that list. Friends in lists that are switched off will not be able to see that you are online or chat with you, nor will you be able to see whether they are online."
However, if I open the Facebook iPhone app, and go to the chat view, I can see everyone who is online, regardless of whether or not they have placed me in a group that is set to offline. Note that this only occurs in the iPhone app - the website chat view is fine.
Can anyone else replicate this?