Silly, Naive Me

I'm puzzled by Instapundit's post on the "planted question" brouhaha. Lots of people that otherwise are pretty level-headed are getting all upset over this. But would it have been seemly for either CNN or Google to vet the questioners ahead of time? Wouldn't suppressing a question just because somebody was a supporter of a democratic candidate be seen as pitching softballs at the candidates? And shouldn't the candidates all be big boys and girls and be able to field questions from the opposition? If they're sensitive about the Other Side gunning for them in the primaries, where they presumably have a pretty friendly audience, what are they going to be like the general?