New Zealand Man Buys MP3 Player with U.S. Troop Data

A New Zealand man who bought a used MP3 player from an Oklahoma thrift store found names, cell phone numbers, and Social Security numbers of American soldiers on the device, according to news site TVNZ.
Source: CNET News
Calling all encryption to active duty. What goes through peoples' heads?
I guess I can't really wrap my head around why this kind of data would end up on an MP3 player in the first place. But if there was a good reason (or even a bad reason), please -- get that stuff encrypted. I simply cannot believe that the person who transferred this data to the MP3 device wasn't aware of encryption policies covering this kind of thing.