Here's a report from a friend on how she was pickpocketed on the Athens Metro last week. Watch out for "helpful" strangers:
"It was in a very crowded Metro train at the Akropolis stop in Athens. The train was jam packed. The doors opened, and two (or four) arms reached out and literally lifted us onto the train. I smiled at the nicely dressed man for being so helpful. He gave me a wide grin back. When we got off the train my (zipped shut, carried frontally) purse was too light. My wallet and phone had been surgically removed from it, and it had been re-zipped shut. Bob's phone had been lifted out of his front pocket without his noticing. Fortunately our passports were back in the hotel room and one credit card and one debit card were tucked safely into a money belt Bob had buttoned under his shirt."