I think the nanny state charge is appropriate when people engage in dangerous behavior (like riding a motorcycle without a helmet) where almost all the risk of

I think the nanny state charge is appropriate when people engage in dangerous behavior (like riding a motorcycle without a helmet) where almost all the risk of the potential harm is taken on by the user. With large cars its the opposite. The people who drive large cars take on no risk, while everyone else is subjected to their negative externalities.