When normal people get a pornbot follower on Twitter, they think "ew," or maybe "ha," or, at the very most, "now I've arrived." But some time ago, when some political strategist got his very first pornbot follow, he thought, "what an excellent campaign tactic!" At Election Law Blog, Rick Hasen flags research from Indiana University about how campaigns use "astrotweeting" to bad info about their rivals. 

One case study of a rumor that Chris Coons, the Democratic nominee for Senate in Delaware last fall, uses tax dollars to attend fancy fashion shows:
This is one of a set of truthy memes smearing Chris Coons... Looking at the injection points of these memes, we uncovered a network of about ten bot accounts. They inject thousands of tweets with links to posts from the freedomist.com Web site. To avoid detection by Twitter and increase visibility to different users, duplicate tweets are disguised by adding different hashtags and appending junk query parameters to the URLs. This works because many URL-shortening services ignore querystrings when processing redirect requests.
 
To generate retweeting cascades, the bots also coordinate mentioning a few popular users. These targets get the appearance of receiving the same news from several different people, and are more likely to think it is true, and spread it to their followers. Most of the bot accounts in this network can be traced back to a single person who runs the freedomist.com Web site. The diffusion network corresponding to this case is illustrated in Figure 7(D).
Coons's opponent, Christine O'Donnell, used the mostly-false claim against him twice during a debate, saying he spent $53,000 to go to a "men's fashion show." But Coons actually spent $3,000 to go to a fundraiser for a youth group that included a fashion show.
 
Via Teagan Goddard, Hasen has more here.