While travelling on the Prague subway, we started to board the car when about ten individuals dressed all min black appeared in back of myself and 3 of my party. they shoved me into the car where I was surroundsd and my arms lifted up. My wallet which was in my back pocket was lifted with no sense of feel. Luckily one of my party saw what was happening and bedgan grabbing the large bags the group was carrying. I YELLED FOR POLICE AND BEGAN MAKING NOISE. I think our reaction was not expected because the wallet was suddenly on the floor in front of me. By now we were at the next stop and the group got off. DO NOT KEEP WALLETS IN BACK POCKETS. KEEP THEM IN MONEY BELTS OR POUCHES UNDER YOUR SHIRT.