I've been swabbed there, tested positive for something, had to have a secondary screening of the bag (everything out and checked). No idea what set it off. I've also been randomly selected for secondary bag checks by an agent, so it certainly isn't a case of men only - I don't know what guidelines they are given to ensure they are random, maybe that agent on Sundays in December picks men during 01-30 mins, and women 31-00 mins? That would be a fairly 'random' way of doing it. Maybe on Tuesdays he picks people with gold jewelry / watches for the first half hour and silver jewelry / watches for the second half hour. It's very hard for people to really pick people randomly, so maybe they have little checks / balances to help them make determinations that are not predictable to those who want to act maliciously. Or, alternatively, maybe they had a credible threat about a male passenger so there was nothing random about it. As for "I saw men who were obviously not dangerous " what utter garbage, you cannot possibly make such a determination from looks, and I am glad that security personal don't make the same assumptions.