I'm the type of person who doesn't give a **** if I offend people, so I quite happily stood there and called people around me out very loudly. "You know what you're doing, I know what you're doing" etc etc. The security at Covent Garden were clearly wanting to act, but only really did it once people started to become vocal. My actions caused a lot of ruffled feathers, to the point where the guys organising the scalpers came over from across the road and tried to get the Apple staff to quieten me down. What it did though was draw attention to what was going on, I was then vocal about how they did it and called/pointed out more, that spurred the security and apple staff to start throwing people out of line.
Kudos to Covent Garden, they are doing all they can.