" We can't have your people fighting each other," I said. The 'royal we' is very important in police work; it reminds the person you're talking to that behind you stands the mighty institution that is the Metropolitan Police, robed in the full majesty of the law and capable, in manpower terms, of invading a small country. You only hope when you're using that term that the whole edifice is currently facing in the same direction as you are. "

― Ben Aaronovitch , Rivers of London (Rivers of London, #1)