Big political implications in this Ian Urbina piece in NYT’s Sunday Review:

Other bots have more underhanded ambitions. Last year, officials from Mexico’s governing Institutional Revolutionary Party were accused of using bots to sabotage the party’s critics by appropriating some of their hashtags and flooding Twitter with identical posts, designed to trip Twitter’s spam filter. Believing the posts to be spam, Twitter soon began blocking those hashtags entirely, temporarily silencing the critics, which was exactly what the government officials intended.

In 2010, researchers with Truthy, the Indiana University research group, discovered a number of Twitter accounts sending out duplicate messages and re-tweeting messages from the same few accounts in a closely connected network. Two accounts, for example, sent out 20,000 similar tweets, most of them linking to, or promoting, the Web site of John A. Boehner, then the House minority leader, before the last midterm elections.

Much of the social media remains unregulated by campaign finance and transparency laws. So far, the Federal Election Commission has been reluctant to venture into this realm.