Pickpockets usually work in gangs, most of the time formed by two or three members. While one creates a distraction, the other one dips into the victim's pocket. A group is also a big help to hide the actions of a guilty hand, when the metro is crowded and there is a lot of possible witnesses. But I came to wonder if all these efforts were not futile. Next time you use public transportation, just look around and you'll understand what I mean.
No need for someone else to create a distraction: iPhones are doing just fine! Nowadays, people are so caught up in playing Angry Birds, texting a friend or updating their Facebook profile that they don't have a clue of what is happening around them. They keep in touch with everyone but are oblivious to people close by. Any pickpocket just needs to reach out and help himself. Not only is the victim not paying attention, but so is everyone else... no witnesses.
I understand that the 30 minutes ride to work can be tiresome and that you need to entertain yourself or keep your mind busy, but remember that it makes you a vulnerable target for thieves. So unless you wish your next Facebook status to be "Just been robbed", pay closer attention to your surroundings!
With my experience - and I honestly think I am slowly starting to gain some, seeing as putting something into a pocket can sometimes be just as difficult as taking something out of it - I can assure you that a pickpocket feels a lot more confident when he knows that no one is looking at him...