My take on the post that you linked to is that it is wrong to vote on individual nodes based on the author (or any other arbitrary criterion). However, the "take away 5 XP" button doesn't alter the XP of any existing nodes; it just takes 5 away from your total. So, in essence, the bot that I proposed would not be a vote bot insofar as the bot isn't voting on anything. Moreover, the potential for abuse is slim; if someone wanted to be malicious with this, they'd have to know the know the password of their atackee. There are far more interesting things to do with someone's password...