Hey guys,
For a mod I am making I was think of having enemies that react the same way as the snipers do in operation anchorage, that is, when you get within the specified area, previously hidden and unagressive snipers begin to fire upon you. After searching through the Geck I still can't figure out how to get this to work for my snipers. If anyone knew how this process works it would be quite helpful. ^_^

Look up the scripts associated with Arkansas over at Minefield. He'll start shooting cars if you get near them- even while undetected. I'm sure that you can modify the script to make them shoot the PC instead of nearby objects.

Well the thing was is that I was making an "Operation Anchorage Hardmode" mod, which would include more snipers. However you did raise a good point and I think i'll look into that.