Regarding the Aug. 18 article "In anonymous packed train lurk gropers": Hong Kong's crowded commuter trains also have gropers, and the Mass Transit Corporation is seriously thinking of adopting women-only carriages during rush hour to combat this obnoxious problem. This would be very similar to the system now operating in Japan.
Groping, or molesting, is nothing new, though. Forty or so years ago, Hong Kong's extremely crowded buses were the main means of public transport. My wife, a local schoolgirl at the time, tells of a method she employed against male predators on buses. In her schoolbag she carried a sewing kit used as part of her school activities. When troubled by a groping situation, she would quickly produce a couple of needles and push them into the offending hand or whatever. Reaction was almost instantaneous — and she traveled on undisturbed! Perhaps this should not be recommended for Japanese consumption, and I am not suggesting that women passengers be issued needles. It does show, though, that you should never upset a young Chinese girl.