Front bumpers with airbags

A post started off in another forum that brought up a question. I've heard that drilling into a bumper on a truck that has airbags COULD set them off if you get lucky. First off is this true. Second off if it is how can it be avoided. Are there wires or sensors that need to be avoided or is everything tucked back into the frame somewhere. Right now I'm wishing I got airbags just so I can go find out....this questions getting on my nerves.

Here's a copy of the thread for all who wants the whole story.
http://www.explorerforum.com/forums/showthread.php?threadid=19551