First of all, I would never do this. I've heard of contractors drilling holes in the outer 2/3's of trusses, for running wire in the floor space of useable attics, and leaving the middle third alone, but it sure seems to me that a hole drilled through a truss in ANY location could seriously compromise the integrity of the truss.

I'm posting this because I have a nosey, "unhelpful" neighbor who keeps coming around, wanting to help me with my addition (2x4 trusses), and when he saw me running 12/3 wire along the face of the trusses, and stapling them every couple of feet, he asked why I didn't just drill holes through the dang trusses and stick the wire through them. I sure would like to hear yalls opinions on this. Seems like a no-brainer to me, but I've been wrong many, many times before.