We reached Rome by train (thanks to Eurail pass) and within moments of getting off the train someone stole my valet! This is despite the fact that, I had kept the valet in my front pocket (which also had a zipper). The speed with which this happened took me off-guard.
I understand that such thieves act in coordination - one person would be responsible for distracting the victim and the second would do the actual act of stealing.
This is how (I presume) it happened in my case. I took the metro pass from the vending machine and started waking towards the train. Just then I saw a lady (who was walking past me), 'accidentally' drop a book. It was quite a heavy book and the sound of it hitting the floor was hard to miss. I was surprised that the lady did not realize this and prompted her about the same.
It was probably during this that I got robbed. Having successfully distracted my attention, her accomplice would have easily taken my valet. The accomplice would have noticed where I had kept my valet after taking the metro ticket.