Promising to defeat a terrorist group isn't controversial, but Donald Trump's idea for a strategy how might be his worst, ugliest idea yet. Trump made a call-in appearance on Fox News this morning, with the discussion quickly moving to how he'd handle the threat posed by ISIS. After vaguely promising he would "knock the hell out of them," one Fox anchor asked Trump, "What about civilian casualties?"While Trump seemed to start off saying he would want to avoid civilian casualties, he quickly pointed out that members of ISIS sometimes use civilians as shields, before making a horrifying suggestion. "When you get these terrorists, you have to take out their families," he said. "They care about their lives, don't kid yourself. But they say they don't care about their lives. You have to take out their families."If you're wondering why "take out their families" sounds familiar, it's a normal battle plan in Mafia movies, not a military strategy from presidential candidates.The Fox News anchors, notably, looked shocked at this new Trumpism, with Elisabeth Hasselbeck starring open-mouthed before trying to shift the discussion to anything else. Just add it to the list of terrible ideas from the GOP leader.