my recollection of the "cowboys" in the original key to the players in the shango stuff was that they were thought to be....
"*Cowboys=Americans searching for Natalee; her family, EquuSearch, FBI, etc."
http://ragingbull.lycos.com/mboard/boards.cgi?board=CLB01002&read=6937
Yes...that is what most believed to be the case. I agree.