And I am with Apple on this one, for the existence of this choice. If you have a list where dragging of single items is prevalent, you should disable it. But if you have a list where making contiguous selection is more common, it should be active. In those situations you tend to click, hold and drag downwards to extend the selection and don't to drag anything. So the meaning the gesture of clicking and dragging isn't unique and this preference lets the Cocoa programmer decide which behaviour is more appropriate in his application. It's good to have that choice, but perhaps it wasn't well made in iChat.
E-mail addresses and comment forms are handy.
Received data seems to be invalid. The wanted file does probably not exist or the guys at last.fm changed something.