"However, since the vandals had no evidence against her, she hadn't done anything wrong, and it was simply a case of, as the link put it, "extraordinary ignorance", this really doesn't have much to do with vigilantism."

actually it was everything, vigilantism is not a science, give a man a gun and tell him to kill the latest person who got released from prison on child molestation offence is hardly the greatest idea. the man maybe innocent after all, he was released for a reason maybe by planted evidence, maybe by new evidence or alibi, maybe by a technicality but at the end of the day and the people do not have the right to play double jeproady on a man they do not feel justice has been done if he was found innocent or not proven, that is for the courts (and if you are christian) god to take care of. not people for whom they think a man's live is there to take as they wish.