I don't believe that the ad urged anybody to shoot anybody at all, nor do I think Sarah targeting their seats did, or Kos putting a "bulls eye" on them, or any of the other people who focused on the seats in question. Kos doesn't like her for blue-dogging it, Sarah for her caucusing with the Ds...
It's all good really. They were just gimmicks to get people out to vote, or to convince people not to vote for somebody and nobody, even this lunatic, ever went out and did anything to any of these people because of these gimmicks.
I've seen other ads with that image, usually whey they are a "target" of an investigation or some other nonsense. It's pretty old hat, so was Sarah's website list, and Kos's list. The only reason that Sarah's list got some notice was because she's Sarah.