Last year there was a big push to get the communications system up and running again in Iraq. I know someone who worked in Iraq for a large well-known company that often does government contract work. Berg was a free-lancer, but evidently worked like a sub-contractor, and hired his services out to firms like these. And I'm sure they paid him fairly well.
I thought it had been reported that he was not employed or contracted with those companies. Also, the tone of his emails home suggest to me that he was dealing with locals and not with anyone operating under the coalition. That is in line with suspicions apparently strong enough to get him hauled in by someone or another in Iraq.
[All that and the fact that his old man makes me want to believe the worst of the entire family.]