Side note to subway systems and being a foreigner in them.

I had my pocket picked (wallet stolen) in mexico city's metro.

Then I remember somebody saying "that's why I carry my wallet in the front pocket".

I'll be darned if my wallet was picked less han a week later from the front pocket, and I didn't feel a thing.

Carry an el cheapo dummy wallet with maybe the metro map and a couple euros, and keep anything valuable in a belt wallet. Not a wallet with a string that goes around your waste, but a thin single compartment zipper wallet with a belt loop that goes on your belt and tucks in your pants.

And if you cannot enter the subway car with at least 1 or two feet of personal space, you are probably being attempted to be pick pocketed. If there are a ton of people pushing to get on the car, you are probably being pick pocketed. Do not try to be the first on the car, rather hang back and let ohters in first...