On the ground and in the air, not much is known, and facts are few and far between.
"Since 1998, more than 20 private contractors have died in Colombia, and their deaths have hardly been mentioned."
http://onlinejournal.com/artman/publ...ter_1785.shtml
http://www.americas.org/item_15405
http://www.ciponline.org/colombia/contractors.htm