I once heard a story, possibly an urban (aviation?) myth, that a pilot said ... "and we're currently passing overhead Liverpool, so hold on to your wallets..."
In the version I heard the pilot got into trouble with the Management, although I heard it again and was told there were 30 odd (stone cold sober I'm sure) Liverpudlian football fans on board.... eek.
A locked and reinforced flight deck door suddenly becomes your best mate in the world!