Now Playing: 08-08-12 Marketplace Tech Report

Mitt Romney is being followed by robots. Seriously. On Twitter. The presumptive GOP nominee recently saw a dramatic spike in his follower count: 116,000 in just one day. Most of those followers, however, are fakes. Twitter is crawling with fake people. Why? Money. And while these bots are mostly harmless, the technology is improving, making it increasingly difficult to tell who's real or who's not.