There were some news reports early on of insurgents going into people's houses, rounding up the family, and sending out a family member to blow themselves up, under the threat of execution of the rest of the family if they didn't do it.

I think most of the insurgents are actually a lot less willing to give their own lives than one would think, especially from the combat reports I've seen - they basically open up, and then as soon as they take fire, dissapear and fade into the population. Standup shootouts pretty much don't happen.