We recently changed flights from LHR hrough to Havana at Barajas, Madrid, without comming out to the landside. We had to go through an additional security scanner in a tiny space in the basement. The staff were really rude and unpleasant. They took away the water everyone had just bought for the plane thinking they were already through security, and would not even let us drink it. They took away duty free and subjected it to tests for some reason. They had to call someone down from elsewhere in the airport to do this and there was a considerable delay which could have resulted in someone missing a flight. There was no explanation at all. Same thing happened in both directions.These were the nastiest airport staff I have met for a very long time, very unpleasant indeed. It left a lalsting impression on me. So don't buy water or duty free when you land in Madrid.