Maybe not so nefarious. Back in the 1980s the campus phone system at my university had a similar quirk: if you didn't hang up both ends of the call, the connect

Maybe not so nefarious. Back in the 1980s the campus phone system at my university had a similar quirk: if you didn't hang up both ends of the call, the connection stayed open. A common DOS prank was to call someone and then just not hang up. Their phone was then unusable.