The bag searcher called someone else over and they asked me to go and wait by a separate table - the 'naughty table' I expect it's called - while they called via intercom for a bag tag. When this arrived, the guy suggested that it would be easier to handle in a bag, so I emptied my backpack of anything remotely valuable and they checked that. I didn't see any boxes but that doesn't mean they don't have any. Everyone was very polite and they are probably used to being shouted at, I just smiled and apologised.