Para Bellum, have any of those cardboard IPSC targets ever shot back at you? Or, heaven forbid, fired at you before you knew they were there?
Okay, didn't intend to be overly sarcastic there, just (hopefully) getting your attention right off the bat. I too was once an IPSC shooter who wondered the same thing. A few dozen sessions of paintball, followed some years later with uber-kool Force-on Force training (Airsoft) convinced me that cover is a very good thing to head for asap.