It's complex.
On the one side one can argue that these people have jobs, shelter, food, clothing, etc. and that those buying the iPhones/PSP's/etc help make this possible. On the other side one can argue - like this journo - that those buing iPhones/PSP's/etc create and supports a form of modern slavery.
It's similar to the arguments around using domestic servants in SA ... creating a job vs. harsh realities (very low pay, harsh transport realities, etc).
Too be without a job (no income, no food, etc) must be the worst state of the two, but it does make me think about what others had to endure for me to have the iPhone. Around Christmas one need to consider these things as we hand over those credit cards and cash in exchange for the things we so desire.