Recently we flew to the Maldives with Etihad. On the return flight to Abu Dhabi the flight was overbooked, by which I think they meant that economy was overbooked. The check-in staff had overridden our pre-booked seats and gave us different seats. Their reason was the overbooking, but I couldn't understand what that had to do with it.
Is it normal practice that check-in staff can ignore pre-booked seats and put you elsewhere?