Fark had a pretty good article written by the Christian Science Monitor regarding checkpoints, worth a look-see in my opinion.
What Iraq's checkpoints are like
That being said, I highly doubt this woman was targeted.
There are a couple of stories floating around, in Italy, not here, that they never told the U.S. because they knew how we would react to paying a ransome.
Either way, at night, I don't think the troops could've known who was in the car.
If they didn't know, how could this not be an accident as this woman claims?
On a side note: I'm not too happy about hearing ransomes being paid, that ain't gonna help anything.