A metric assload of Journey tunes

Seeing this gallery of NYC folks in headphones, I was reminded of just how many little white earbuds I saw the last time I walked around New York City. During the morning rush near  Times Square, I could have sworn at least 1 in 10 people walking around had an iPod going.

Then the thought occured to me -- if 1 in 10 people have an ipod in the morning, and there are hundreds of thousands of people going to work, and each iPod has anywhere from 5 gigabytes to 40 gigabytes of storage, what's the estimated total temporary storage of music, across all of Manhattan each and every morning?

Are we talking many, many terabytes? Or are we talking even petabytes of music storage?