Women Only

Japanese trains and subways are famous for being overcrowded, and you often hear about the dirty old men who take advantage of the situation by groping young women. Apparently the problem is bad enough that some train lines have instituted a "no men allowed" policy in certain cars, where women can enjoy their morning commute without fear of unwanted touching and other lecherous advances.

Now, I'm as opposed to sexual assault as the next privileged white male, but this sounds like a clear case of reverse discrimination to me. Does this mean that any women riding on co-ed trains when there is space available in a ladies-only car are fair game?