> This really hasn't anything to do with list ownership -- but does
> anyone know whether that notice actually achieves anything?  Strikes
> me the sensible thing might be to campaign internally to get it
> removed.  Anybody ever seen a notice like it?

I haven't. I would say if I receive a message (in error) that had that on it, I would
be more inclined to scrutinize the message and look for something I shouldn't be
looking at. Whereas if it wasn't there, I would be more inclined to delete it faster.
If there was delicate info there, how many people would actually do as instructed
anyway?  Like everyone would take the time to send it back rather than delete it?
Rediculous!