While often the thieves do have their work cut out for them when it comes to harvesting data, sometimes we make it all too easy. No surprise to many, a common source of data for fraudsters in Nigeria to use has been recycled computers. Most people aren't aware that simply deleting a file is nowhere near enough to prevent its recovery, and as such think it's no big deal to ship an unformatted disk off. Good intentions aren't always rewarded, as people who have become victims in this fashion are aware. Recycled PCs are very commonplace, as well:

Real Story found that second-hand computers from all over the developed world could be found in virtually every PC market in Nigeria's commercial capital of Lagos. It said that while there was a genuine market for second-hand PCs in West Africa, identity fraud was a real problem.
A word of advice to anyone getting rid of old hard drives, make absolutely sure those disks are clean. A Windows format does nothing to remove data. When it doubt, take a hammer to the disk before giving the rest of the hardware away.