At the LHR trial (I'm 99% sure of this) they have one machine operated by a man and one operated by a woman, and the people the pull out of each security line will be either all male or all female, depending on who is operating the machine. Can anyone else confirm this? I wasn't paying complete attention at the time but thinking back now I'm almost sure that the 4-5 people that went ahead of me were all male too, but the other line had women only...