I've been playing in IDP leagues for almost 20 years and the one constant observation I hear from league members who are new to to the IDP format is that there is no downside for defensive players. Offensive players can be penalized for INT's and fumbles. Kickers can be penalized for missed FG's and XP's. But IDP's are never penalized. All biscuit, no risk-it
But can they be? My league has discussed the possibility of assessing negative scoring to defensive players via infractions. For example, a 5 yard penalty (offsides, defensive holding) would assess -1 pts. 10 yard penalties would be -2 pts. 15 yards or more would result in -3 points. So far we haven't found this option in my ESPN league, so I'm not sure it's even a configurable option in other FF host formats.