Back in the days of character-based server applications we had the problem of users switching off their monitor at night & wandering off home (or maybe someone else's home - who knew?) without logging out. We had a motd that reminded users to log off but that didn't always influence behaviour. Eventually we added "This includes you $name" and changing the name whenever we discovered someone else logged in. The message got through fairly quickly and the time between name changes got longer until the last miscreant's name was their so long their manager rang and asked us to remove it.